Stock price decreases prior to executive stock option grants

Journal of Corporate Finance7200153–76

https://www.sodocs.net/doc/e43786849.html, r locate r econbase

Stock price decreases prior to executive stock

option grants

Keith W.Chauvin),Catherine Shenoy1

School of Business,Uni?ersity of Kansas,Lawrence,KS66045,USA

Accepted20November2000

Abstract

This study examines abnormal stock price changes prior to executive stock option grants. Executives have the incentive and opportunity to manage the timing of their communications of inside information to the market during the period just prior to the date of their stock-option grant so as to reduce the exercise price of their options.Executives benefit from temporary stock price decreases before the grant date and by stock price increases after the grant date.Executive stock option grants create a unique opportunity for insiders to profit by manipulating the timing of information flowing to the market without engaging in insider https://www.sodocs.net/doc/e43786849.html,ing data on783 stock-option grants to chief executive officers,we find a statistically significant abnormal decrease in stock prices during the10-day period immediately preceding the grant date.q2001Elsevier Science B.V.All rights reserved.

Keywords:Stock option;CEOs;Compensation

1.Introduction

Insiders generate and process fundamental information about the value of the firm. Their decisions,communications and other actions all convey information to the market, and stock price changes reflect the market’s valuation of the information.Given inside information as well as discretion over how and when the market will be informed,

Corresponding author.Tel.:q1-785-864-7567.

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E-mail addresses:kchauvin@https://www.sodocs.net/doc/e43786849.html, K.W.Chauvin,cshenoy@https://www.sodocs.net/doc/e43786849.html, C.Shenoy.

1Tel.:q1-785-864-7519.

0929-1199r01r$-see front matter q2001Elsevier Science B.V.All rights reserved.

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PII:S0929-11990000019-5

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–76

insiders have knowledge of both the direction and timing of future price changes. Insiders may appropriate for themselves at least a portion of the value of the expected

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price changes by buying selling based on the knowledge that current prices undervalue ?.

overvalue the firm.Those insiders who are willing to engage in insider trading base their decisions of when to trade on their knowledge of when good news or bad news is forthcoming.2

In this paper,we consider a unique situation where the timing of insider buying activity is fixed by a third party—the board of directors.When the board of directors grant stock options to executives,they give insiders the right to buy stock at a fixed exercise price sometime after the option grant.The board’s intent is to align the executives’interests in the value of the firm with those of shareholders.3Stock-option compensation rewards executives for maximizing the difference between the exercise price of the options and the stock price.Once the exercise price of the options is fixed, all price increases increase the value of the option and represent gains to the executive. Stock options,therefore,give insiders an interest in maximizing the long-term stock price.

There is an unintended incentive associated with executive stock options,however, around the time the options are granted.The exercise price of the options is normally fixed at the market price of the stock on the day the options are granted.Since the exercise price of the option is the price at which the executives may purchase the stock, executives have an incentive to temporarily decrease the market price of the stock on the day of the option grant in order to decrease the exercise price.They do not have an incentive to harm the firm’s reputation or permanently decrease the stock price.With this motivation,we expect only short-term transitory effects.

One way of affecting the stock price is by manipulating the timing of good news and bad news.Bad news represents a forthcoming decrease in the stock price.An insider who knows that both stock-option grants and bad news are forthcoming,will prefer, everything else the same,that the market learns of the bad news prior to the option grants.For the same reasons,the insider will prefer that the market learns about forthcoming good news,which represents a forthcoming price increase,after the option grant.It is in their interest,therefore,to convey to the market prior to the option grants any bad news they may have,and delay informing the market until after the grants of any good news that may be forthcoming.In effect,by manipulating the timing of when

2The terms good news and bad news are used throughout this paper to categorize types of information. Information that increases stock price is defined as good news,and information that decreases stock price is defined as bad news.We are not attempting to describe the form of the communication by using the term news.News is information that may be communicated through formal or informal https://www.sodocs.net/doc/e43786849.html,rmal methods can include rumor,innuendo,and other means that are not easily attributable to a single person.We expand this idea later in the paper.

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According to The Conference Board’s1993annual survey of top executive compensation,stock options are the most widely used form of long-term compensation for executives.In1992,over50%of firms in each industry sector used stock option plans for executives.The median grant of options to the top five executives, as a percent of the base salary,ranged from195%in the diversified services industries to123%in the trade industries.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7655 the market is informed of good and bad news,the insider is manipulating the timing of the price changes associated with the good and bad news.

The initial idea for this study grew out of a conversation we had several years ago with a former vice president of a large publicly traded firm.The conversation took place following the presentation of a paper regarding the disincentives for insiders to use their private information for the benefit of shareholders.The executive commented that during the time just prior to the annual stock option grants in his former firm,top executives would A stand around hoping that nothing good happened B that would cause the stock price to increase significantly prior to the grants.They would even talk openly about their concern that something good could spoil their options.We posit that for some executives,incentives lead to actions,not just hope.

In this paper,we investigate the hypothesis that grants of stock options may lead insiders to take actions to reduce the likelihood of anything good happening prior to the grants.Executives who expect to be granted stock options have the incentive,opportu-nity and ability to affect the exercise price with their inside information.4The purpose of manipulating the timing of price changes would be to reduce the exercise price of the stock without having a long-term detrimental effect on the value of the firm.As long as the exercise price is lower than what it would have been but for the manipulation,and there is not an equal or greater effect on the stock price during the window in which the executives can exercise their options,then insiders profit from such manipulation. Furthermore,since the stock options are awarded by a third party,the board of directors, the insiders profit from this manipulation without buying or selling the stock during the time the price is reduced.

To test whether or not bad news is being released prior to the option grants,we look at stock price changes during the pre-grant period.Some may argue that a more appropriate test would be to look for the actual announcements,i.e.,formal news releases,that convey the bad news to the market.Such an approach,however,would fail to capture the complexity of how information is communicated from insiders to the market.Insiders may communicate bad news to the market through rumor,innuendo, formal announcements or by simply failing to disclose good news when the market is expecting good news.Given the subtlety and complexity of how information is communicated,it is impossible to measure directly the communications themselves. While the communications being sent by insiders are difficult to measure,price changes constitute an excellent measure of the value of information being received by the market.Price changes,which reflect the market’s valuation of news regardless of the form of the news and net of expectations already reflected in the price,are certainly far superior than our interpretations of news releases or other communications from insiders.

4Throughout the paper we use the term incentive to mean that there is a positive expected financial benefit for executives from the manipulation of the timing of information flowing to the market.Such actions, however,may not be utility improving for many or even most executives because of the disutility of not being ethical or honest.How many or how often executives will manipulate information for their own benefit is an empirical question.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–76 We test for this unintended effect of executive stock option grants by estimating abnormal returns during the10-day period prior to the stock option grant date for783 option grants to chief executive officers.If insiders effectively manipulate information around the time stock options are granted,prices should be lower at the time of the options grants than would otherwise be expected.We find a statistically significant decrease in stock prices during this time period,with most of the decrease occurring during the3trading days immediately preceding the grant date.While this analysis does not constitute a direct test of why stock prices are,on average,lower than expected on the option grant date,the results are consistent with information being manipulated by insiders.

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This study is similar to Yermack1997,which also looks at price changes around stock option grant https://www.sodocs.net/doc/e43786849.html,ing a sample of option grants between1992and1994,his study finds abnormal price increases during the50-day period following the option grants.Yermack interprets this finding as evidence that CEOs influence the timing of the compensation committee meeting to ensure that options,are granted prior to the release of good news that the CEOs know is forthcoming.In the current study,we hypothesize that insiders opportunistically manipulate the flow of information given a fixed and

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known grant date.Yermack1997hypothesizes that insiders opportunistically manipu-late the timing of the grant date given a fixed and known flow of information.

Regardless of whether the timing of information or the timing of the grant date is being manipulated,the insiders benefit if bad news reaches the market prior to the grant date;and good news—after the grant date.The price declines preceding the grant date found in the current study and the price increases following the grant date as reported in ?.

Yermack1997are consistent with both the information manipulation and grant date manipulation hypotheses.

In order to distinguish between these two hypotheses,we conduct further analysis. Many of the CEOs in our sample received multiple option grants over the12-year period represented in the sample.We observe that the options are often granted on exactly the same day of the year as the previous year’s grant,or that the grant date varies by only a few days around the previous year’s grant.In other words,it is clear that options are often granted on a regular and predictable schedule.If the unexpected price changes around the grant dates are due to the timing of the grant date being manipulated,we would not expect to observe abnormal changes in those cases where the options are being granted on approximately the same date each year,i.e.,on the day of a pre-scheduled compensation committee meeting.We estimate the abnormal returns for those options that appear to have been granted on a predictable date.The abnormal price decreases prior to option grants are larger that the decreases found in the overall sample. We interpret this finding as being inconsistent with Yermack’s hypothesis that the abnormal price changes are due to the manipulation of the timing of the meeting date.

In the next section of the paper we review the option granting process,the unintended incentives created by process,and how insiders can manipulate information in order to take advantage of these incentives.In Section3of the paper we describe the data, methodology and results.Finally,in Section4we summarize the paper and discuss a few mechanisms that compensation committees could use to reduce the executives’ability to adversely affect stock prices prior to stock option grants.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7657 2.Option grants and incentives

2.1.The option granting process and short-term incenti?es

Stock option compensation is intended to reward executives for maximizing the market price of the stock.The gains to the executive are realized when the options are exercised.Option compensation at the exercise date is:

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Option compensation s P y X n,for P)X,

where P s market price of the stock on the exercise date;X s exercise price determined on the date options are granted;and n s number of options exercised.

Options provide executives the right to buy stock at the exercise price normally between1and10years after the grant.Once options have been granted,executives capture a portion of the value created for shareholders from any decision that increases P.While the intent is for executives to maximize the long-term stock price,P,the process followed by most boards of directors in issuing stock options and setting the exercise price gives executives an opportunity to benefit from actions that lower X as long as such actions do not lower P by an equal or greater amount.It is the process that boards of directors and compensation committees follow in granting options that provides an opportunity for insiders to focus on X prior to the option grants.

Before stock options can be granted,the board of directors must bring the general policy of granting stock options as compensation to a vote by the shareholders.After the policy is approved,the board then determines which executives are eligible for option grants.The board typically assigns the year-to-year administration of executive compen-sation including the granting of stock options to eligible executives to a compensation committee.5Compensation committees typically meet three to five times per year to consider all executive compensation issues.At least one of these meetings is designated for making decisions about incentive pay.During this meeting,the compensation committee determines the number of stock options to grant based on pre-set criteria in the compensation plan.Most options are then granted as of the day of the committee meeting with an exercise price based upon the market price of the stock at the close of trading on the day of the meeting.6

There are several institutional reasons why the options are granted on the day of the meeting.First,tax and accounting rules require the recognition of an expense if the grant is issued‘in-the-money’,i.e.,at a lower price than the current stock https://www.sodocs.net/doc/e43786849.html,ing the closing price of the grant day guarantees that the firm will not have to record an expense,which will decrease earnings.The second reason that compensation committees

?use the meeting date is to avoid charges of opportunistically picking a grant date such 5?.?.

See Bacon1993and Mitman1985for description on the roles and responsibilities of compensation committees.

6Very few firms base the grant price on a formula that sets the exercise price based on performance relative to the market or industry.However,the formula price cannot be lower than the closing price on the grant day.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–76

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as October19,1987that rewards a CEO for reasons that have little to do with managerial performance.7

As a byproduct of this process,executives know the date when options will be granted.Top executives know when compensation committee meetings are scheduled, and in many cases the meeting is on the same day every year.While the CEO is not usually a member of the compensation committee,he is often given the opportunity to provide the committee with input pertinent to the incentive pay decisions being made by the compensation committee.Such input may include the CEO’s performance expecta-tions for the firm and industry,and her knowledge of compensation trends in the industry.

Given knowledge of when the compensation committee will meet to decide on details of the option grants,executives have an incentive to reduce the exercise price of the stock as long as their actions do not have a long-term detrimental effect on the value of the firm.In the next section,we consider how executives can affect short-term stock prices by manipulating the timing of good news and bad news.

2.2.Manipulation of insider information

The incentives and opportunities for executives near the stock option grant date are similar to the incentives and opportunities of those who engage in insider trading. Insiders who trade time their trades to coincide with the good news or bad news about which they have private knowledge.For stock option grants,the timing of the trade is fixed by the compensation committee.Given a fixed date,an insider can use discretion over private information to affect the timing of when the market becomes informed of the good news and bad news.

Manipulating the timing of information is equivalent to manipulating the timing of stock price changes.This type of information manipulation is similar to information-based manipulation of stock prices.In the debate over the informational efficiency of insider trading,several studies have considered how insiders can enhance the value of their inside position by manipulating stock prices.Stock price effects can occur when security markets use insider trading as a signal of the value of private information.Insiders ?.

Kumar and Seppi,1992,and even outsiders who can mimic the trading patterns of an ?.

insider Allen and Gale,1992,can manipulate stock prices through their trading activity.More relevant to the issues in this paper is price effect from information-based manipulation.As long as the public announcements of insiders are taken as truthful,

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insiders can also manipulate stock prices by releasing false information Jaffe,1974;

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Vila,1989;Bagnoli and Lipman,1996;Benabou and Laroque,1992.Insiders gain from

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information-based manipulation of stock prices by selling buying following the release

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of false information that increases decreases stock prices.

7While we were unable to find studies or detailed descriptions of the institutional practices of compensation committees.Two consultants specializing in executive compensation,however,confirmed through telephone interviews that the compensation committee’s review of incentive pay and stock options occurs on an annual basis and information regarding the date of the meeting is available to the CEO and other members of the management team.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7659 There are numerous cases of egregious manipulation of stock prices by insiders who release false information to a public that assumed the announcements were truthful.The insiders then traded in the stock between the time of the announcement and the time the truth was determined by other traders.One of the most widely cited cases of this form of manipulation is documented in SEC v.Texas Gulf Sulphur,1968.8In the Texas Gulf case,the company discovered rich mineral deposits on company-owned property in Canada.The company took explicit action to disguise the discovery including the moving of drilling rigs and public announcements that mineral deposits had not been found.During a4-day period between the release of false information and the announce-ment that a substantial mineral deposit had in fact been found,insiders and others with inside information bought substantial numbers of shares in the company.Following the truthful announcement of the discovery,price increased rapidly.

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This form of manipulation is not a recent innovation.Benabou and Laroque1992 describe the manipulation of banker,Nathan Rothschild,who engaged in both trading-based and information-based price manipulation during the Battle of Waterloo.Roth-schild had access to better information than the public about the success of the battle and knew the battle was going well.Despite his information,Rothschild was openly selling

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British government securities trade-based manipulation and issuing statements that the

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battle was not going well information-based manipulation.At the same time he was manipulating the price,Rothschild was privately buying large number of securities.

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In a model of insider trading,Benabou and Laroque1992show that insiders maximize the benefit to private information by not only trading on the basis of information,but also by controlling the timing and quality of information flowing to the market.Benabou and Laroque address the conditions under which an insider,or others who may have privileged information such as a journalist,can be less than truthful with

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their information and still retain their credibility.Building upon Sobel’s1985model of credibility,they show that the optimal behavior for an insider who has a reputation for being honest but who is willing to be less than honest,is to use up at least a portion of their reputation by repeatedly mixing biased and unbiased messages to the market.As long as the information that is being released is noisy,the insider will be perceived as being wrong,rather than dishonest.Benabou and Laroque argue that insiders can repeatedly manipulate information.

When executives know the date that stock options will be granted,they do not have to resort to the release of deceptive information.With little risk to their reputations, executives can profit by manipulating the timing of information received by the market. They can rush bad news to the market or delay the release of good news.Furthermore, executives do not have to resort to formal public announcements in order to inform the market.Insiders can put a more negative‘spin’on information than otherwise,speak ‘off the record’to analysts,or strategically use rumor and innuendo to‘leak’informa-tion.Indeed,the least overt method of communicating with the market may be to simply

?. delay an announcement the market is expecting to occur.Chambers and Penman1984

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and Kross and Schroeder1984,for example,find negative abnormal price effects See Manne,1966,or Jaffe,1974,for a more detailed account of the Texas Gulf case.

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caused by delays in earnings announcements.The failure to announce,when an announcement is expected in this case,is interpreted by the market as bad news.Of course,insiders more than willing to risk their reputations could release false informa-tion.False information could be as blatant as the moving of drilling rigs that occurred in the Texas Gulf case,or as simple as issuing earnings forecasts that are biased downward.

For the special case of executive stock option grants,we argue that bad news is more likely to be transmitted using an informal mechanism such as a pessimistic conversation with an analyst or a failure to confirm a positive news story.Executives do not want to spoil their potential compensation packages immediately before the compensation committee meetings by having a formal announcement of bad news,nor do they want the decline in price to be permanent.Price decreases induced by rumor and innuendo can be attributed to misinformation in the market.If executives manipulate information before the option grant,instead of hoping that price changes will favor them,we expect them to use informal communication methods to transmit bad news.

2.3.Measuring the use of pri?ate information

Given the many ways insiders can convey private information to the market,and the subtlety and complexity of many of these processes,the use of inside information is largely unobservable.This difficulty in monitoring the use of inside information creates opportunities for the misuse of inside information and reduces opportunities for direct empirical analysis of the use of such information.How do outsiders determine whether good or bad news,or even whether any news at all,has been transmitted?

Changes in prices result from changes in publicly available information and are commonly used as the appropriate measure of whether or not private information has become public.A typical event study looks at price changes around a well-defined announcement of news.Whether or not the event is well defined,i.e.,the public announcement of information represents information not currently imbedded in the price,is determined by looking for abnormal price changes prior to announcement. Abnormal price changes prior to the‘event date’are interpreted as evidence of information leakage.

Price changes also reflect changes in information that are used to draw inferences

?. about whether the information conveyed is good or bad.Givoly and Palmon1985,for example,in a study of the information content of insider trading,use the direction of price changes associated with announcements to categorize news as good or bad.

The first event study did not look at price changes around a well-defined public release of information,but looked for price changes to infer a non-public release of

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information.Armen Alchian,in Alchian1996,relates a story about working as an economist with RAND in the1950s.During this time,physicists were working on the development of the hydrogen bomb.While the RAND economists knew that the physicists had discovered the essential metal for the bomb,for security reasons the information was kept from the economists.In order to identify the material being used, Alchian looked for price changes among the firms that sold the possible metals being

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7661

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tested by the physicists.Finding a500%increase from US$2to US$13over a4-month period in the stock price of the Lithium Corp.of America,Alchian circulated an internal paper in RAND entitled A The Stock Market Speaks,B revealing that lithium was the ingredient being used.

2.4.Other information effects

https://www.sodocs.net/doc/e43786849.html,rmation about incenti?es

Other possible stock price reactions could occur because of stock option grants.The grant of stock options could be considered good news,but only if grants contained unexpected positive information.The incentive performance plans,which permit the issuance of stock options,must be approved by the shareholders in advance at the annual https://www.sodocs.net/doc/e43786849.html,ually,these plans are approved for a multi-year period.The incentive performance plans usually include some means of determining the number of options granted,and a limit to the total options,which can be granted without further shareholder approval.The valuation effects of using stock options to bond executives to the interests of shareholders should be reflected in the market’s response to the

?. announcement that the firm is adopting this type of plan.Brickley et al.1985found a positive stock price reaction when new long-term incentive compensation plans were announced.It is not clear that the actual option grant by the compensation committee adds any relevant information for the market’s valuation of the firm.

2.4.2.Manipulating the meeting date

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Yermack1997hypothesizes that CEOs can change the timing of stock option grants by influencing the timing of the compensation committee meeting.In order to capture gains from expected good news,Yermack argues that CEOs encourage the compensa-tion committee to grant options prior to the release of the good news.Under his hypothesis,compensation committees are willing participants in the opportunistic timing of the option grants.9Looking at620option grants between1992and1994,Yermack finds abnormal price increases in the50-day period following the grant date.He did not find a significant abnormal price decrease10days before the option grant,but he does not report the cumulative abnormal returns for a shorter period before the grant.

It may not be possible to distinguish between the grant date manipulation and information manipulation hypotheses by simply looking at price changes before and after option grants.Nor is it possible to distinguish between the two hypotheses by using forma announcements such as a Wall Street Journal Article or a press release because CEOs in this case will be more likely to use informal information channels.We examine the frequency of formal announcements and attempt to control for the timing of the grant date in part our analysis reported below in Section3.6.

9Our conversations with consultants specializing in executive compensation and executives themselves indicate that it would be very difficult to co-ordinate a change in the date of the compensation committee meeting.Most compensation committee meetings are scheduled up to a year in advance.

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2.4.

3.Dilution effect

The maximum number of options that can be granted and the criteria for the grant is set in the incentive compensation plan which must be approved in advance by shareholders and is usually in effect for a number of years.The valuation effects of using stock options to bond executives to the interests of shareholders are reflected in the market’s response to the announcement that the firm is adopting this type of plan.

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Brickley et al.1985found a positive stock price reaction when new long-term incentive compensation plans were announced.A possible negative reaction could occur if more options were granted than expected;however,the negative reaction would occur on or after the grant date,not before.

Stock option grants might also be considered bad news because of the stock dilution which will occur when the options are exercised.Again,however,such a negative reaction should occur following the announcement that the firm has adopted a policy of using stock option plans,rather than when the options are actually granted.In fact,?.

Brickley et al.1985find a positive effect net of any dilution of the stock value.The primary uncertainty around the option grant date is the number of options to be granted, so we would not expect a reaction until after the compensation committee meeting which occurs on the grant date.

3.The methodology and results

3.1.The sample

Over the past10years,CEO compensation reporting has received criticism and scrutiny from such diverse groups as the popular press,activist shareholders,academic

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researchers,the Securities and Exchange Commission SEC,foreign politicians,the US

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Congress,and the Financial Accounting Standards Board FASB.In the1980s,the level of CEO pay increased rapidly,while in some cases,the financial performance of the company declined.At the same time shareholder activism of large outside sharehold-ers increased.The link between CEO pay and firm performance became the focus of much debate.

This increased scrutiny led to several changes in compensation reporting require-ments.Executive compensation disclosure rules dating from1983were the result of a 9-year experiment by the SEC in‘free-writing’.The intent had been to report the main features of executive compensation without including too many technical details.Annual proxy statements were required to report the number of executive stock options granted in the year and the gain from any options that were exercised during that year.In various ways companies also reported on the exercise price of the options granted and https://www.sodocs.net/doc/e43786849.html,ually the proxy statement reported the average exercise price of all outstanding options.Only a few companies reported the actual number of option grants and exercise price during the year.In this situation it is possible to determine the current value of the option grants.However,most often the exact exercise price,the time to

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7663 expiration,and the number of options granted were reported as an average for all outstanding options.This type of reporting made it difficult to determine the value of CEOs stock option compensation using standard option pricing models.

In response to investor criticism and political pressure,the SEC adopted new reporting requirements in October1992.The current rules require a table of compensa-tion for the CEO and the next four highest paid officers and a graph of stock performance compared to the S&P500and an industry index.Option grants require a separate table reporting the number of options granted,the exercise price,the expiration date,the value of the options for stock price changes of5and10%,and the present value of the options.In another table the gain from the options exercised during the year must be reported.In addition the value of all unexercised options is reported using the ending stock price at the fiscal yearend.

In addition to recent proxy changes,SEC insider trading reporting rules for executive stock options which are covered under Section16of the1934Securities Act changed in May,1991.Before this date the SEC did not require the same reporting standards for the stock and stock option grants to executives.For every stock grant executives were required to file an insider trading report within first10days of the month following the grant.There was no requirement to report option grants.Options,stock appreciation rights and other derivative securities were reported only upon exercise.At exercise they were considered to be a simultaneous purchase and sale of stock.

After May,1991,insiders were required to report option grants on the same basis as stock grants.Stock option data is reported on Table2of Form4or Form5filed under Section16of the1934Securities Act.Data on these forms include the expiration date, the vesting date,the exercise price,and the number of options granted.This act covers insider trading rules and reporting requirements.Executives file SEC Form4whenever they acquire or dispose of securities in their own firm.They file Form5at the end of the year,if no reportable transactions occurred during the year or as a summary.

To obtain data for this study we requested all Forms4and5filed from May1991to February1994for313CEOs.The name of the CEO and the company name was obtained from Forbes annual compensation survey.CEOs were chosen if they had served as CEO for at least5years and data for the company was available on CRSP and Compustat.

May1991was the date of the change of the reporting rule.At that time,CEOs were required to‘catch-up’.So the next Form4that they filed or Form5at the end of the year lists all option grantsthat they held including the expiration date,the vesting date, the exercise price,and the number of options granted.Of the313CEOs,209had filed reports indicating that they had received option grants;51filed reports,but had no options;and41had no report on record.The209CEOs represent a total of830different grants,of these783had complete stock price information.Table1shows the distribu-tion of firms by the number of options granted.The second column reports the number of firms which had from1to12option grants.For example,51firms had only1option grant to the CEO,while1firm had12different grants to its CEO.Column3reports the product of columns1and2.

Fig.1shows the number of grants by year.1991is the year for the most option grants.This is not surprising since then-President-elect Clinton had already proposed tax

Fig.1.Distribution of783stock option grants,by year,for a sample of209firms.

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K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7665 Also,we observe only those grants that had not yet been exercised as of the reporting date.Earlier grants that were exercised were not be reported in the‘catch-up’reporting.

3.2.Estimation method

An event study is used to obtain estimates of abnormal stock returns during the period just prior to the option grant date.A180-day estimation period is used that begins 225trading days before the event date,and ends45trading days before the event date. The event date is the option grant date.Daily abnormal returns are averaged over the

?. sample of783firms yielding the average abnormal returns.We follow Patell1976,

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Linn and McConnell1983among others and calculate standardized abnormal and cumulative abnormal returns.We estimate the abnormal returns using both the equally-weighted and the value-weighted market index.Results are robust using both methods so we report only the equally-weighted market index results.

3.3.Abnormal return results

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Table2reports average Panel A and cumulative average Panel B abnormal returns.During the10-day period prior to the grant date,average abnormal returns are negative each day except for day y10and day y5.The average abnormal return on day y3is y0.21%,which is statistically significant at the1%level.The cumulative ?.

abnormal return CAR between day y10and day0is y0.57%,which is also significant at the1%level.During the10-day period prior to the grant date,the CAR is negative for438firms and positive for only345firms.

Abnormal returns during the10days after the grant date are generally positive.The return on day q1is0.18%,which is significant at the5%level.The CAR for the 10-day period15following the option grant date is0.27%,but is not significant.10A graph of the cumulative abnormal returns between day y10and day q10is shown in Fig.2.

The graph clearly shows the negative abnormal returns during the10days prior to the grant and the upward trend in prices following the grants.These results are consistent with the hypothesis that executives may manipulate the timing of good news and bad news being released to the market prior to the option grant dates.Of course,this is not a direct test of whether or not information is being manipulated.This is an indirect test with price changes serving as a proxy for information.The results after the grant date

?.

are consistent with Yermack1997;however,we do not find any indication of a long-term run-up in stock prices in our sample.Nor are the results consistent with the dilution hypothesis because a substantial amount of the negative reaction occurs over the 9days preceding the grant day,not just on the grant day itself when the uncertainty

We also estimate the results separately for each year.The results indicate that seasonality is not a problem. For11of12years the cumulative abnormal return was negative prior to the grant day,and for11of12years the abnormal return was positive after the grant day.

()K.W.Chau ?in,C.Shenoy r Journal of Corporate Finance 7200153–7667

Fig.2.Cumulative average abnormal return for CEO stock option grants from day y 10to day q 10.

3.4.Economic significance

To determine the economic significance of the these abnormal returns to the shareholder and to estimate an upper bound on the value to the CEOs in the sample of the estimated price decreases prior to stock options,we calculated the dollar value of the abnormal return for each CEO,for each of the 21trading days between day y 10and day q 10.11Weighting the dollar value of the abnormal return by the number of options granted,we find the total value of the abnormal returns during the 10-day period prior to and following the grant date.The dollar value of the abnormal return is calculated as:

Dollar Value s P y E P n

?.jt jt ?.where P is the stock price of the j th firm on day t ,E P is the expected price based jt jt on the estimated market model,and n is the number of options granted.The average dollar value of the cumulative abnormal returns is shown in Fig.3.On average,the dollar value of the cumulative abnormal returns weighted by the number of options,is a loss of about US$20,000for the period day y 10to day 0.Since the exercise price is set on day 0,for CEOs in this sample,the total cost of exercising the options is US$20,000

11

The dollar value is an estimate of the upper bound value to the CEO.To determine the value to the CEO an option pricing model using a known exercise date would have to be used.Since the exercise date is unknown we do not attempt this calculation.If the CEO holds the option until expiration,the value of this strategy will be significantly lower.However,the CEO does have the opportunity to capture most of this value ?.immediately by means of an equity swap.See Willis,1995;O’Brian,1997.

()

68

K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–76

Fig.3.Cumulative dollar value of average abnormal returns for day y10to day q10for CEO stock option grants.12

less than the cost would have been had it not been for the abnormal returns during the period prior to the grant.

Would a CEO of a publicly held firm risk his or her reputation for a US$20,000gain? Since it is often the case that many of the top executives within a single firm are awarded stock options at the same time,this US$20,000average gain may be only a fraction of the total gain to all of the executives in these firms who received options on the same day.Furthermore,and more importantly,it is not argued that all executives manipulate the timing of the information in order to affect short-term stock prices.Only those who are willing to risk their reputation for being truthful and who have useful information to manipulate around the time of the option grant will engage in such activity.It is likely,therefore,that the observed abnormal returns represent the average

w?.x?.?.

The dollar value is calculated as:P y E P n;where P s stock price on day t;E P s expected

t t t t

?.

stock price on day t calculated from the estimation period model;and n s number of options granted.

()

in,C.Shenoy r Journal of Corporate Finance7200169

Fig.4.Distribution of the cumulative dollar value of the day y10to day0average abnormal returns for CEO stock option grants.13

effect of many CEOs who did not manipulate their communications with the market and maybe only a few who attempted to manipulate the short-term stock price.It is also important to recognize that in each of the stock option grants represented in this data set,

?.

it is likely that other insiders top executives also receive stock options.Any one of the

13w?.x?.?.

The dollar value is calculated as P y E P n;where P s stock price on day t;E P s expected

t t t t

?.

stock price on day t calculated from the estimation period model;and n s number of options granted.The labels on the x-axis are the maximum for each range.The range boundaries are"3,000,000,1,000,000,

?. 500,000,400,000,300,000,200,000,100,000,90,000,80,000,70,000,60,000,and decreasing increasing by 10,000to0.For example the bar labeled0counts the number of values occurring from y US$10,000to US$0, and y100,000counts the number of values from y US$200,000to y US$100,000.

()

70

K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–76

insiders receiving options could have affected the information being conveyed to the market.

Fig.4is a histogram which shows that the average negative abnormal values result primarily from outliers at the left-hand tail of the distribution.This figure plots the total dollar value per grant of the cumulative abnormal returns between day y10and day0is shown in Fig.4.The median dollar value of the abnormal returns is about minus US$3000.The distribution of these dollar values appears to be approximately normal between minus US$100,000and plus US$100,000.The noticeable difference between the firms with price increases and those with price decreases occurs in the tails of the distribution.There is a relatively large number of CEOs with a total dollar value in the minus US$100,000to minus US$200,000range.In this sample there are102observa-

?.

tions in the lower tail minus US$100,000or less of the distribution while there are

?.

only52observations in the upper tail plus US$100,000or more.In addition low values are higher in absolute value than the high values.The mean for the lower tail is minus US$320,000,while the mean for the upper tail is plus US$290,000.

A US$20,000gain from manipulating information may not be sufficient to entice CEOs who are earning hundreds of thousands of dollars per year to risk their reputa-tions,but the values represented in the tail of the distribution may be sufficient.Only those insiders who have opportunities to manipulate information and who expect benefits to exceed the costs and risks associated with such manipulation,would be likely to engage in such activity.

3.5.Additional analysis

The purpose of this section is to determine whether our results are caused by the release of news that is not within the discretionary control of the firm or by more informal or private information channels.We argue above that insiders who are being granted stock options have the incentive and opportunity to release bad news,whether the news is true or false,prior to the grant date,and delay releasing good news until after the grant date.We cannot,however,observe the use of private information.While we can observe the formal release of information such as announcements in the Wall Street Journal,this observation does not indicate anything about the information that was not released,information that was released but not covered by the WSJ,the alternative means available to communicate the information,nor the value of the information.The information may well have been released through rumor or innuendo using quasi-public forums such as during conferences or conversations between execu-tives and market analysts.Even with respect to the information that was made public through WSJ announcements,we cannot determine whether news is good or bad without first knowing the market’s prior expectations.We can only infer the effect of the information from the market’s reaction.14We infer from the above results that there is

14Givoly and Palmon,1985,studied the market’s reaction to the first announcement following insider trading to determine whether good news followed insider buying and bad news followed insider selling. Givoly and Palmon classified news as good news if the abnormal return following the announcement was positive,and as bad news if the abnormal return was negative.

()

K.W.Chau?in,C.Shenoy r Journal of Corporate Finance7200153–7671 relatively more unexpected bad news released prior to the option grant dates for the firms in this sample,and relatively more unexpected good news following the grant dates.

Some of the bad news prior to option grants and some of the good news following option grants may have been releases of information that were beyond the control of the firms in this sample.To test whether or not the above findings of negative abnormal returns prior to the stock option grants were caused by information that is not within the discretionary control of the CEO or other top executives we searched the WSJ for announcements relating to the firms in this sample during the10trading days prior to each of the783option grants.There is at least one announcement during the10trading days prior to the option grants for103of the grants in the sample.

We classified these announcements on the basis of whether or not the firm had any discretion over the type of the information or the timing of the release.Examples of discretionary news include announcements about earnings,dividends,forecasts of sales or earnings,expansions or acquisitions,new products,discoveries,patent filings, cancellation of previously announced plans or contracts,and stock splits and repur-chases.Examples of non-discretionary news include litigation filed against the firm, labor disputes and settlements,and the awards of government contracts.Of the103 announcements,82were classified as discretionary,and21were classified as non-dis-cretionary.Of the82discretionary announcements,37were earnings announcements.

Abnormal returns for the10days prior to the option grants were then estimated for four sub-samples of firms.The first sub-sample included those firms with discretionary announcements.The second sub-sample included firms with non-discretionary an-nouncements,the third sample included firms with earnings announcements—a sub-sample of the discretionary announcements,and the fourth sample included the680 firms for which there were no announcements.The results of this analysis are reported ?.

in Table3Panel A.For firms with non-discretionary announcements the cumulative abnormal return during the10days prior to the option grants is0.05%.For the sub-sample of firms with discretionary news the CAR is y0.42%,and for the firms with no news reports the CAR is y0.61%.

There are two purposes for examining formal announcements:one is to determine the importance of formal information transmission mechanisms in this study.Since only82 of the783,or11%of the firms had discretionary announcements,we conclude that formal announcements are not the primary means of transmitting information around the dates of the stock option grants.

?.

Table3Panel B tests the difference in abnormal returns between each type of announcement and the group that had no formal announcements.We do not find any statistically significant difference between any of the groups.

The other reason to examine formal announcements is to determine whether or not the initial findings of negative abnormal returns prior to stock option grants are caused by the release of bad news that is not within the discretionary control of the firm.Based

?.

on the results reported in Table3Panel A,firms with non-discretionary announce-ments prior to a stock option grant have positive CARs,and therefore,those announce-ments do not account for the significant negative returns observed in the full sample of firms.Clearly,from Table3,the firms with discretionary announcements and those

causing the large negative returns.

3.6.Grant date manipulation?s.flow of information manipulation

?.

Yermack1997found abnormal price increases during the50-day period following CEO stock option grants,and cites this as supportive of the hypothesis that CEOs manipulate the timing of the grant date to occur prior to the release of good news. Yermack did not find a significant abnormal price decrease10days before the option grant,but he does not report the cumulative abnormal returns for a shorter period before the grant.The reason for the different findings is not clear.The primary difference in the two studies is the sample period.Yermack’s sample covers only2years of options, 1992–1994,while our sample covers options granted between1981and1992.

More importantly,however,Yermack’s findings are not inconsistent with the hypoth-esis put forth here that insiders may manipulate the flow of good news and bad news to the market around the grant date.Even if insiders are able to opportunistically manipulate the timing of the compensation committee meeting,they would still have an incentive to release bad news prior to the grants.Likewise,a decline in stock prices prior to the grants may be interpreted as consistent with both the grant date manipulation and information manipulation hypotheses.In order to determine whether or not the results we obtained were being caused by manipulation of the grant date,we partitioned our sample in an attempt to control for the grant date.

Most of the CEOs represented in our sample received multiple option grants during the12-year time period covered by our sample.We observed that the CEOs who

Matlab之print,fprint,fscanf,disp函数的用法

print： print函数可以把函数图形保存成图片： minbnd = -4*pi; maxbnd = 4*pi; t = minbnd:0.1*pi:maxbnd; plot(t, sin(t), 'g', 'Linewidth', 2); line([minbnd, maxbnd], [0, 0]); %绘制x轴 axis([-10, 10, -2, 2]) %定义显示的坐标区间:x在(-10,10)之间，y在(-2,2)之间 grid on; title('sin(x)'); xlabel('x'); ylabel('sin(x)'); print('-dpng','sin.png'); %保存为png图片，在Matlab当前的工作目录下 如下： 打开Matlab当前的工作目录下可以看到有sin.png图片了 print('-dpng', 'sin.png')表示保存为png图片，文件名为sin.png，其中第一个参数可以是： -dbmp：保存为bmp格式 -djpeg：保存为jpeg格式 -dpng：保存为png格式 -dpcx：保存为pcx格式 -dpdf：保存为pdf格式 -dtiff：保存为tiff格式

fprintf： fprintf函数可以将数据按指定格式写入到文本文件中： data = [5, 1, 2; 3, 7, 4]; [row, col] = size(data); for i=1:row for j=1:col fprintf('data(%d, %d) = %d\n', i, j, data(i, j)); %直接输出到屏幕；类似于C语言的输出格式end end fprintf(fid, format, data)中的fid表示由fopen函数打开的文件句柄，如果fid 省略，则直接输出在屏幕上，format是字符串形式的输出格式，data是要输出的数据。其中format可以为： %c 单个字符 %d 有符号十进制数（%i也可以） %u 无符号十进制数 %f 浮点数（%8.4f表示对浮点数取8位宽度，同时4位小数） %o 无符号八进制数 %s 字符串 %x 小写a-f的十六进制数 %X 大小a-f的十六进制数 输出到文件： data = [5, 1, 2; 3, 7, 4]; [row, col] = size(data); %求出矩阵data的行数和列数 %加t表示按Windows格式输出换行，即0xOD 0x0A，没有t表示按Linux格式输出换行，即0x0A fid=fopen('test.txt', 'wt'); %打开文件 for i=1:row

第八章 类和对象 复习题知识讲解

第八章类和对象 复习题

第八章类和对象复习题 1.系统为每个类提供一个this指针，在类的成员函数内，通过this指针可以 间接访问这个类的( ) 所有成员 C.友元类的public成员 D.所有派生类中的public成员 2．如果在class类的定义中既不指定private，也不指定public，则系统就默认为( ) A. private B. public C. protected D. 不确定 3. 对静态数据成员的描述, 正确的是( ) A. 静态数据成员可以在类体内进行初始化 B. 静态数据成员不可以被类的对象调用 C. 静态数据成员不能受private控制符的作用 D. 静态数据成员可以直接用类名调用 4. 下面叙述错误的是( ) A. 基类的protected成员在派生类中仍然是protected的 B. 基类的protected成员在public派生类中仍然是protected的 C. 基类的protected成员在private派生类中是private的 D. 基类的protected成员不能被派生类的对象访问 5.对于友元函数的描述，正确的是( ) A. 友元函数的实现必须在类的内部定义

B. 友元函数是类的成员函数 C. 友元函数破坏了类的封装性和隐藏性 D. 友元函数不能访问类的私有成员 6.关于内联函数的描述，正确的是( ) A.使用内联函数可以缩短程序代码，减少占用的内存空间 B.使用内联函数可以减少函数调用时入栈和出栈的时间和空间开销，但是会使程序的代码量增加 C.内联函数只能在类的内部进行声明和定义，不能作为全局函数 D.内联函数可以做虚函数 7. 类是对象的( ) A. 具体 B. 抽象 C. 封装 D. 多态 8. struct声明类时，若不作private或public声明，系统默认为( ) A. private B. public C. protected D. 不能确定 9.引入内联函数的主要目的是( ) A.缩短程序代码，少占用内存空间 B.既可以保证程序的可读性，又能提高程序的运行效率 C.占用内存空间少，执行速度快 D.使程序的结构比较清晰 10. 类的具体表现是通过定义来操作的。对象 11．说法错误的是（） A．一个类是由一批数据以及对其操作的函数组成

print类型函数详解

print类型函数详解 printf()函数是格式化输出函数系列中比较有具有普遍特点的, 一般用于向标准输出设备按规定格式输出信息。在编写程序时经常会用到此函数。printf()函数的调用格式为: printf("<格式化字符串>", <参量表>); #include #include int main() { char c, s[20], *p; int a=1234, *i; float f=3.141592653589; double x=0.12345678987654321; p="How do you do"; strcpy(s, "Hello, Comrade"); *i=12; c='x41'; printf("a=%d", a); /*结果输出十进制整数a=1234*/ printf("a=%6d", a); /*结果输出6位十进制数a= 1234*/ printf("a=%06d", a); /*结果输出6位十进制数a=001234*/ printf("a=%2d", a); /*a超过2位, 按实际值输出a=1234*/ printf("*i=%4d", *i); /*输出4位十进制整数*i= 12*/ printf("*i=%-4d", *i); /*输出左对齐4位十进制整数*i=12*/ printf("i=%p", i); /*输出地址i=06E4*/ printf("f=%f", f); /*输出浮点数f=3.141593*/ printf("f=6.4f", f); /*输出6位其中小数点后4位的浮点数f=3.1416*/ printf("x=%lf", x); /*输出长浮点数x=0.123457*/ printf("x=%18.16lf", x);/*输出18位其中小数点后16位的长浮点数x=0.1234567898765432*/ printf("c=%c", c); /*输出字符c=A*/ printf("c=%x", c); /*输出字符的ASCII码值c=41*/ printf("s[]=%s", s); /*输出数组字符串s[]=Hello, Comrade*/ printf("s[]=%6.9s", s);/*输出最多9个字符的字符串s[]=Hello,Co*/ printf("s=%p", s); /*输出数组字符串首字符地址s=FFBE*/ printf("*p=%s", p); /* 输出指针字符串p=How do you do*/ printf("p=%p", p); /*输出指针的值p=0194*/ getch(); retunr 0; } 上面结果中的地址值在不同计算机上可能不同。

Matlab之print,fprint,fscanf,disp,input函数

Matlab之print,fprint,fscanf,disp， input函数 print： print函数可以把函数图形保存成图片： 1minbnd = -4*pi; 2maxbnd = 4*pi; 3t = minbnd:0.1*pi:maxbnd; 4plot(t, sin(t), 'g', 'Linewidth', 2); 5line([minbnd, maxbnd], [0, 0]); %绘制x轴 6axis([-10, 10, -2, 2]) %定义显示的坐标区间:x在(-10,10)之间，y在(-2,2)之间 7grid on; 8title('sin(x)'); 9xlabel('x'); 10ylabel('sin(x)'); 11print('-dpng','sin.png'); %保存为png图片，在Matlab当前的工作目录下 如下： 打开Matlab当前的工作目录下可以看到有sin.png图片了 print('-dpng', 'sin.png')表示保存为png图片，文件名为sin.png，其中第一个参数可以是： -dbmp：保存为bmp格式 -djpeg：保存为jpeg格式 -dpng：保存为png格式

-dpcx：保存为pcx格式 -dpdf：保存为pdf格式 -dtiff：保存为tiff格式 fprintf： fprintf函数可以将数据按指定格式写入到文本文件中： 12data = [5, 1, 2; 3, 7, 4]; 13[row, col] = size(data); 14for i=1:row 15 for j=1:col 16 fprintf('data(%d, %d) = %d\n', i, j, data(i, j)); %直接输出到屏幕；类似于 C语言的输出格式 17 end 18end fprintf(fid, format, data)中的fid表示由fopen函数打开的文件句柄，如果fid省略，则直接输出在屏幕上，format是字符串形式的输出格式，data是要输出的数据。其中format可以为： 19%c 单个字符 20%d 有符号十进制数（%i也可以） 21%u 无符号十进制数 22%f 浮点数（%8.4f表示对浮点数取8位宽度，同时4位小数） 23%o 无符号八进制数 24%s 字符串 25%x 小写a-f的十六进制数 26%X 大小a-f的十六进制数

打印和打印机设置函数

打印和打印机设置函数 打印函数用于在打印机上格式化输出数据。这组函数与各对象的Print()函数有所不同，程序在使用这组函数时，需要使用PrintOpen()函数打开一个打印作业，然后根据需要执行这组函数中的一个或多个函数，最后使用PrintClose()函数关闭打印作业。 打印机设置函数用于得到当前的打印机名称，设置应用程序使用的打印机，得到系统中包含的所有打印机，显示打印机设置对话框等。 1、Print() 功能：以当前字体在打开的打印作业中打印一行或多行文本。 语法：Print(printjobnumber,{tab1,}string{,tab2}) 参数：printjobnumber：用PrintOpen()函数打开的打印作业号； tab1：Integer类型，可选项，指定文本开始打印的位置，在开始打印字符串之前将打印光标移动到该位置，从打印区的左边界开始计算，以千分之一英寸为单位。如果打印光标已经位于指定位置、或打印光标已经超过了指定位置、或省略了该参数，那么，Print()函数从打印光标的当前位置开始打印string：string类型，指定要打印的字符串。如果字符串中包括回车换行字符（~r~n），那么该字符串将被分成多行输出，但是，除第一行之外，其它行忽略tab1参数指定的起始打印位置； tab2：Integer类型，可选项，指定字符串打印结束后打印光标移动到的位置，从打印区的左边界开始计算，以千分之一英寸为单位。如果打印光标已经超过了指定位置，那么Print()函数忽略该参数，打印光标位于已打印字符串的尾部。如果省略了该参数，Print()函数把打印光标移动到下一行的起始位置； 返回值：Integer。函数执行成功时返回1，发生错误时返回-1。如果任何参数的值为NULL，Print()函数返回NULL。

Python 3 print 函数用法总结

Python 3 print 函数用法总结1.输出字符串和数字 >>>print("runoob")# 输出字符串 runoob >>> print(100)# 输出数字 100 >>> str = 'runoob' >>> print(str)# 输出变量 runoob >>> L = [1,2,'a']# 列表 >>> print(L) [1, 2, 'a'] >>> t = (1,2,'a')# 元组 >>> print(t) (1, 2, 'a') >>> d = {'a':1, 'b':2} # 字典 >>> print(d) {'a': 1, 'b': 2} 2.格式化输出整数 >>>str = "the length of (%s) is %d" %('runoob',len('runoob')) >>> print(str) the length of(runoob)is6 支持参数格式化，与C 语言的printf 类似 python字符串格式化符号:

格式化操作符辅助指令: 3.格式化输出16进制，十进制，八进制整数%x --- hex 十六进制 %d --- dec 十进制 %o --- oct 八进制

>>>nHex = 0xFF >>> print("nHex = %x,nDec = %d,nOct = %o" %(nHex,nHex,nHex)) nHex = ff,nDec = 255,nOct = 377 4.格式化输出浮点数(float) >>>pi = 3.141592653 >>> print('%10.3f' % pi)#字段宽10，精度3 3.142 >>> print("pi = %.*f" % (3,pi))#用*从后面的元组中读取字段宽度或精度 pi = 3.142 >>> print('%010.3f' % pi)#用0填充空白 000003.142 >>> print('%-10.3f' % pi)#左对齐 3.142 >>> print('%+f' % pi)#显示正负号 +3.141593 5.自动换行 print 会自动在行末加上回车, 如果不需回车，只需在print 语句的结尾添加一个逗号 , ，就可以改变它的行为。 >>>for i in range(0,6): ... print(i,) ... 1 2 3 4 5 6.print 不换行 在Python 中print 默认是换行的 >>>for i in range(0,3): ... print(i)

python 3 Print函数用法实例详解

Print函数用法实例详解 Python 思想：“一切都是对象！” python3和python2中print的用法有很多不同，python3中需要使用括号，缩进要使用4个空格（这不是必须的，但你最好这么做），缩进表示一个代码块的开始，非缩进表示一个代码的结束。没有明确的大括号、中括号、或者关键字。这意味着空白很重要，而且必须要是一致的。第一个没有缩进的行标记了代码块，意思是指函数，if 语句、 for 循环、while 循环等等的结束。后面我们将陆续介绍。今天我们先通过实例学习print函数的用法。 语句格式： print(*objects,sep="",end="\n",file=sys.stdout,flush=False) 参数注解： 1.objects: 之所以是复数，表示可以一次输出多个对象。输出多个对象时，需要用,分隔 举个例子: 程序 a1="aaa" a2="bbb" print(a1,a2,) 运行结果：aaa bbb 2.sep=" " 用来间隔多个对象，默认值是一个空格。你可以设置成其他字符。在print 函数中，所有非关键字的参数都会被转化成字符型。 举个例子: 程序： print("aaa","bbb",sep="hello") print("aaa","bbb",sep="word") 运行结果： aaahellobbb aaawordbbb 两个字符串不用,隔开就会当做一个字符串。 3.end="\n" 这个参数的作用很明显，用来设定以什么结尾。默认值是换行符，我们可以换成其他字符串。用这个选项可以实现不换行输出： 程序： a1="aaa" a2="bbb" print(a1,end="") print(a2) 运行结果： aaabbb

Visual Basic里与Print有关的函数

Visual Basic里与Print有关的函数 在Visual Basic里信息要按一定的格式输出，需要使用tab、Spc、Space$函数，这些函数必须与Print方法配合使用。 1.Tab函数 格式：Tab(n) 功能：把光标移到由参数n指定的位置，从这个位置输出信息，输出的内容放在Tab函数的后面，并用分号隔开。 (1)参数n是一个整数，它是下一个输出位置的列号，最左边的列号为1。 (2)当在一个Print方法中有多个Tab，每个Tab函数对应一个输出项，各 输出项之间用分号隔开 2.Spc函数 格式：Spc(n) 功能：在Print方法中，用Spc函数，可以跳过n个空格。 (1)参数n是一个整数，其取值范围为0～32767的整数。Spc函数与输出项 之间用分号隔开。 (2)Spc函数和Tab函数作用类似，而且可以互相代替。二者有区别：Tab

函数是从左端开始计数，而Spc函数只是表示两个输出项之间的间隔。 3.空格函数Space$ 格式：Space$(n) 功能：返回n个空格。 4.格式输出函数Format 用格式函数Format，可以使数值或日期按指定的格式输出。 格式：Format(数值表达式，格式字符串) 功能：按“格式字符串"指定的格式，输出“数值表达式”的值。 说明： “格式字符串”是一个字符串常量或变量，它由专门的格式说明字符组成。 (1)#(数字占位符)：表示一个数字位，不在前面或后面补。#的个数决定了 显示区段的长度。 (2)0(数字占位符)：与#功能相同，只是多余的位以0补齐。 (3).(小数点)：根据字符串的位置，小数部分多余的数字按四舍五入处理。 (4)，(千位分隔符)：逗号。在格式字符串中插入逗号起到“分位"的作用。

print函数

printf输出格式 (一)使用printf输出各种格式的字符串 1.原样输出字符串: printf(“%s”,str); 2.输出指定长度的字符串,超长时不截断,不足时右对齐: printf(“%Ns”,str);–N为指定长度的10进制数值 3.输出指定长度的字符串,超长时不截断,不足时左对齐: printf(“%-Ns”,str);–N为指定长度的10进制数值 4.输出指定长度的字符串,超长时截断,不足时右对齐: printf(“%N.Ms”,str);–N为最终的字符串输出长度 –M为从参数字符串中取出的子串长度 5.输出指定长度的字符串,超长时截断,不足时左对齐是: printf(“%-N.Ms”,str);–N为最终的字符串输出长度 –M为从参数字符串中取出的子串长度 ★d格式符,用来输出十进制整数. ⑴%d,按整型数据的实际长度输出. ⑵%md,m为指定的输出字段的宽度,数据位数小于m,左边补空格,若大于m,按实际长度输出 ⑶%ld,输出长整型数据(long) ★o格式符,以八进制输出整数(不带符号,他将符号位也作为八进制数的一部分了) ⑴%o,参考%d的解释. ⑵%lo,参考%ld的解释. ⑶%mo,参考%md的解释. ★x,X格式符,以十六进制输出整数 也是3种参考%d的解释. ★u格式符,用来将unsigned型数据,既无符号数,以十进制形式输出 ★c格式符,输出一个字符. ★s格式符,输出一个字符串. ⑴%s,如printf(“%s”,”CHINA”) ⑵%ms,输出的字符串占m列,字符串长度小于m,左边补空格,如果超出则全部输出.

⑶%-ms,串小于m,则在m列范围内字符串左靠,右补空格. ⑷%m.ns,输出占m列,但只取字符串左端n个字符.这n个字符输出在m列的右边,然后左边补空格. ⑸%-m.ns,和上面的放下,就是n个字符输出在m列的左侧,右边补空格.n>m,那么m自动取n 的值,既保证n个字符正常输出. printf(“%3s,%7.2s,%.4s,%-5.3s “,”CHINA”,”CHINA”,”CHINA”,”CHINA”); ★f格式符,用来输出实数,以小数形式输出. ⑴%f,全部输出,而且输出6位小数. ⑵%m.nf,输出数据共占m列,n位小数,如果数据长度小于m那么左边补空格 ⑶%-m.nf,和上面的m.nf相反,为左靠齐,右补空格. ★e,E格式符,以指数形式输出实数 ⑴%e,不指定输出数据所占的宽度和数字部分的小数位数. ⑵%m.ne和%-m.ne,这里n指小数部分的位数 ★g,G格式符,用来输出实数,它根据数值大小,自动选择f格式还是e格式,(选占宽最少的一种),且不输出无意义的0.这种格式用的不多.