Analysis of Earning Announcements and Security Returns relationship in the frame of the event study methodology

 

Askhat Azhikhanov

PhD student, Institute of Economics and Business,

Kazakh State Technical University Satpayev K.I. (Almaty, Kazakhstan),

e-mail: Askhat@ababank.com

Tel: + 855 23225333 (office), + 855 98890777 (mobile), +855 23216333 (fax)

 

Abstract

The primary objective of this research is to investigate the earnings - price relationship in the frame of the event study methodology. Using the sample of 30 Small Cap and 30 Large Cap companies publicly traded on the London Stock Exchange Main Market the study finds that Small Caps companies do react stronger to Good and Bad news announcements, while Large Caps companies are less responsive to these events.

Key words: stock, earnings news, price, stock returns, small and large cap companies

 

Introduction

Earnings – price relationship is one of the most robust anomalies in asset pricing literature. It is characterized as the continuance of abnormal returns in the direction of earnings news after earning announcements. Early studies try to interpret earnings – price relationship in the context of efficient market theories (EMT) but fail to fully account for the observed price drift. Recent research works have leaned toward behavior finance and attribute the cause of earning – price anomalies to investors under – reaction to earnings news (e.g. Bernard and Thomas (1989, 1990), Barberis, Shleifer, and Vishny (1998), and Daniel, Hrsleifer and Subrahmanyam (1998))

The key implications for the accounting and finance research and policy from the analysis of EMT were the following: first, financial statements are not the only source of information for making investment decisions; second, and more important, no trading advantages accrue to users of financial statements because the information contained in them is instantaneously incorporated in prices as soon as the information becomes public.

Modern Portfolio Theory (MPT) and Capital Asset Pricing Model (CAPM) contributed extra ideas, implying that since the expected return for a given firm does not depend on risks that can be diversified away, information regarding the outlook for a specific firm was largely irrelevant. The only thing that mattered was the systematic risk of the firm and its relationship to the total portfolio. Furthermore, CAPM and MPT influenced accounting theory development by providing a model to measure the reaction of market returns and earnings. Deviations from expected earnings could be shown to influence the realised rate of return or, more specifically, the unexpected portion or abnormal return.

All this led to the so-called market-based research studies that can be classified into the following categories:

§     Tests of the EMT versus classical approach

§     Tests of the informational content of accounting alternatives

§     Tests of the earnings/return relationships

The focus of my work is to test the earnings/return relationship in the frame of the event study methodology. I will therefore proceed in the following way: firstly, I will briefly review the landmark research papers that are directly relevant to the questions I am attempting to answer. Secondly, I will formulate my own hypothesis test and describe the methods and data set I intend to use during my analysis. Thirdly, I will conduct the tests, describe the obtained results and try to interpret deviations from the hypothesis. Finally, I will summarise my findings and suggest if any further tests should be carried out in the following area.

I. Theory and empirical evidence

I will start my review of the research literature from the 1968 paper by Ball and Brown that is thought to be the first comprehensive attempt to analyse the earnings/price relationship. The two academics partitioned the firms in their sample into good news/bad news groupings. Based on a firm’s reported earnings, a company was classified as reporting good (bad) news if the reported earnings were above (below) those predicted by a time-series forecasting models. Based on this classification, two portfolios were constructed. The findings were summarised in the comparison of the cumulative return of the “good news” portfolio versus “bad news” portfolio. Good news firms enjoyed on average abnormally positive returns, whereas bad news firms experienced abnormally negative returns. By this research Ball and Brown demonstrated a clear association between earnings and stock market reaction.

These results, as it often happens with empirical studies, have raised more questions than were answered. Ball and Brown estimated that 80% to 85% of the abnormal market performance occurred prior to the publication of the annual report. This suggests that although earnings are meaningful measures of a firm’s financial performance, by the time they are published they are outmoded and have little or no market impact.

The market anticipated of reported earnings raised questions about the timeliness of annual reports, and spurred a series of studies intended to examine the “information content” of accounting data, which is measured by market reaction to the announced earnings and its deviation from the expected earnings.

To date, studies of the earnings/return relationship are among the most widespread form of market-based research. Some research conducted in this area was very broad in scope; some simply replicated the previous studies, with an emphasis on methodological refinement. But all in all, there has not been achieved rounded understanding of the role of accounting earnings in the stock-return generating process.

The nature of the research can be classified based on the initial study by Ball and Brown into:

§     Accounting variable

§     Market-based variable

§     Tests of the relationship between good news/bad news parameter and abnormal returns

Let us look in more detail into these three groups.

1)      Accounting variable

Ball and Brown used the sign of forecast error of annual net income and earnings per share (EPS). Other researchers, like Beaver at al., considered the magnitude of the error. Further, Foster examined quarterly earnings and found that quarterly reports also possess information content.

However, a later research by Ball (1978) began to document postannouncement drift, where positive (negative) abnormal return patterns continued for some time after the announcement of good (bad) news quarterly earnings.

2)           Market-based variable or measurement period for market performance

Ball and Brown examined monthly returns over full year. Other studies, depending on the issue analysed, used weekly (or daily) returns in the periods immediately surrounding the announcement. The trade-off between using narrow versus wide windows is that in the former case there is less risk that the market could be reacting to information other than that being tested.

3)           Test of the relationship between good news/bad news parameter and abnormal returns

Early studies, as I already mentioned above, grouped firms into good news and bad news portfolios based on the sign or magnitude of the earnings forecast error. Later studies explicitly related the response of stock returns to earnings by the introduction of the earnings response coefficient (ERC).

The ERC is the coefficient b in the regression equation R = a + b∆E, where R and ∆E measure returns and earnings change (growth) respectively. ERCs were typically found to be much lower than expected.

ERC studies tested for differential reaction across firms and to various components of earnings. Collins and Kothari (1989), for example, show that risk and growth variables explain some of cross-sectional differences in ERCs.

 

 

 

Critical evaluation of research findings

Despite the fact that many of the research papers tested relationships that have not been tested before, many, like Lev, were critical to the prior research results because they contribute to neither:

·               An understanding of how and to what extent earnings are used by investors, nor

·               The debate of accounting policy makers

To a great extent, they attributed this failure to a fixation on the part of researchers on sophisticated statistical techniques at the expense of specification of fundamental relationships. This means that studies with statistical significance often exhibited little or no economic significance. For example, it was revealed that studies that examine the earnings/return relationship tended to report low R2. On average, earnings could explain no more than 5% of the variation in returns.

As a result of these criticisms, Lev, among others, suggested a more enhanced approach to the research of return/earnings relationship that should incorporate the following elements:

·               More careful analysis of valuation models as they relate to accounting and earnings

·               Measuring earnings/return relationships on an individual basis rather than portfolio basis

·               Averaging reported earnings over time and examining longer time horizons

·               Earnings components used in the research should incorporate all possible adjustments in order to arrive at a more comprehensive and meaningful analysis.

When discussing the shortcomings of the research in the area of earnings/return, I have to mention a number of discovered market anomalies that question the validity of the EMH and some of the conclusions from the research papers mentioned above. Below are a few of these market anomalies:

·               Monday effect. After the weekend, marker prices tend to open at lower levels, suggesting an advantageous strategy of selling short at the Friday close and covering the short position Monday morning. This anomaly is often used by companies that make their earnings announcement after the Friday close.

·               Price-Earnings Ratio. Firms with low P/E ratios tend to outperform the market even when returns are adjusted for risk.

·               Size effect. Smaller firms (measured by total assets or total capitalisation) tend to outperform the market even when returns are adjusted for risk.

·               The size effect is often attributed to the fact that fewer analysts follow smaller firms than larger firms. Thus, not all information available about these firms is immediately incorporated in stock prices, leaving room for abnormal returns to be earned by those who trade on this information early enough.

·               Post announcement drift. The EMH holds that stock prices adjust instantly to new information. Empirical evidence, however, suggests that price changes persist for some time after the initial announcement. In addition, some researchers found the drift to be less pronounced for stocks having large institutional holdings. However, little relationship was found between investor sophistication and abnormal returns.

·               Over reactive markets: Contrarian Strategy. If the stocks were ranked by their performance over a previous five-year period (the base period), those firms with the worst base-period investment performance outperformed those firms with the best base-period performance over the next three years. This suggests that markets overreact.

This argument was further extended showing that when a firm’s earnings decline, the market overreacts, driving the price down (and the book-to-market value up) sharply. Similarly, when a firm reports good earnings, the market chases the stock price up (and the book-to-market value down). Over time, the extent of overreaction becomes clear and prices reverse, yielding above-(below-) average returns for high (low) book-to-market firms.

I would like to conclude my brief review of research works in the area of earnings/price by describing another study, by Ou (and later by Ou and Penman), because their research contrasts Ball and Brown, discussed earlier.

Ou, similar to Ball and Brown, divided firms into good- and bad-news categories, based on the previously reported earnings. The researcher then added forecast earnings into the picture (derived from the regression using eight variables, various accounting measures), which resulted in the formation of four portfolios.

Portfolio

Reported this year

Predicted next year

E+F+

Good news

Good news

E+F-

Good news

Bad news

E-F+

Bad news

Good news

E-F-

Bad news

Bad news

This research is different from many other studies mainly for two reasons. First, the analysis is not motivated to show whether accounting information is associated on an ex post basis with market prices, but rather whether the information can be used ex ante as a basis for valuation. Second, Ou broadens the set of accounting information by utilising the tools of fundamental analysis (meaning that more attention was paid to changes in accounting policies, ratio and warning signals analysis).

In the following research Ou and Penman tried to see whether a trading strategy based on earnings forecast could prove to be fruitful. It was: the average market-adjusted return was 14.5% per annum over a 24-month holding period.

Finally, I would like to stress that approaches used by Ou and Penman as well as by other researchers do not use fundamental analysis itself. In turn, they rather utilise some of its tools. Fundamental analysis requires more in-depth analysis, the nature of which varies from firm to firm. This important attribute is missing from these studies, and this makes approaches used by many academics significantly different from market practitioners like company analysts.

 

II Sample, hypothesis and methodology

In this section, I first discuss the data, hypotheses and then present methodology I used to test these hypotheses.

Data

As the aim of this course work is not to conduct a comprehensive research study, but rather to demonstrate understanding of the earnings/price anomaly, the choice of the firms included in my sample as well as questions raised are not new for the academic thought.

I work with the sample of 60 companies, a half of which are small-cap firms and another half are large-cap firms. All companies are publicly traded on the London Stock Exchange Main Market. The sample was created based on the market capitalisation of firms: I opted for 30 top and 30 firms with capitalisation below ₤100 million in the list, excluding the financial companies.

The share price information and FTSE ALL SHARES Index return was obtained using Bloomberg and Datastream databases. “Event”, which is the announcement day of the annual earnings (results) of the firm, was sourced from Bloomberg and London Stock Exchange. Both the actual and expected EPS were provided by Bloomberg.

The events in the sample cover the period from 2005 to 2006. Narrowing the sample to 1 year I intend to avoid discrepancies due to market sentiments – the period from 2004 to 2006 period was characterised by predominantly bullish mood with short periods of bearish behaviour.

Annual reports used for interpretation of the earnings/price relationship were obtained from the companies’ websites or from the Bloomberg database.

Hypothesis

I have formulated my hypotheses in the following way:

·               The share prices of the companies with earnings announcements above the market expectations exhibit increase in the prices by percentage of earnings surprise.

·               The share prices of the companies with earnings announcements below the market expectations exhibit decrease in the prices by percentage of earnings surprise.

·               Small-cap firms react stronger to positive (negative) announcements than large-cap firms.

In expanding my analysis, I further examine the market over-reaction and under-reaction to positive (negative) earnings news, as well as, market reaction to non-earnings information.

Methodology

In this paper I use the standard event study methodology to assess the market reaction to the earnings announcement.

The incorporation of earnings information tested within the 21-day period, 10 days before the announcement and 10 days after the announcement. The reason for that selection is the fact that there can be insider trading or leakage in the market and the market can react prior the day of the earnings announcement. I also use the longer event window in order to analyse the post-earnings behaviour of the share price and examine the market over-reaction and under-reaction to positive (negative) earnings new. At the same time, in order to capture the price effects of announcement, I use following event window (-1, 0, +1), where 0 represents the earnings announcement day. I include day -1 and +1 due to the fact that earnings announcement reported in various sources. As a result the information may have been incorporated in share price not only on day 0, but also on day -1 and +1depending on the sources (e.g. broker, news media, etc.).

In order to calculate the abnormal return I use FTSE ALL SHARES index return as a benchmark return. In this case I assume that the share prices move in the same way and proportion as the index. Thus, the abnormal return was calculated for each day and event as the daily log return of each company minus the daily log return of FTSE ALL SHARES index for the same period.

E(Ri) = Rmt                                        ARit = Rit - Rmt

The price reaction on the earnings announcement was measured by the three day cumulative abnormal return (CAR 3 DAYS) and calculated as the sum of abnormal daily return of each company over the following event window (-1, 0, +1). In order to examine the market over and under reaction I also calculate the post announcement cumulative abnormal return (CAR POST) as the sum of abnormal daily return for the post announcement 10 days, excluding abnormal return of the first day (+1). This result will be compared with the CAR3 days around the day of announcement. If:

1.            CAR3 days > CAR POST – then I observe over-reaction to the announcement;

2.            CAR3 days < CAR POST – then I observe under-reaction to the announcement.

In order to investigate the influence of the earnings announcement on the share price I analyse the sign of unexpected earnings change, i.e. deviation of the actual earnings from the expected earnings (earnings surprise). I do not observe the deviation of the actual earnings from the actual earnings the prior year, assuming that all the information about the company is available during a year and most of the content of annual report (about 85 to 90 percent, Ball and Brown 1968) already incorporated in share price based on 3 interim reports. Thus, what really affects the share price on the day of earnings announcement is unexpected earnings change or Earnings Surprise. To calculate Earnings Surprise I use following formula:

Earning Surprise =

In this case, if the actual returns are higher than the estimated ones, then I can consider this news as positive news and the opposite, if the actual are lower than estimated.

I further split the two broad samples of small and large cap companies into three new sub categories based on the sign of earnings surprise: Good news, No news, and Bad news. I categorize the news according to the deviation of the actual earnings from estimated.

·               2.5% increase, considered Good News Event;

·               2.5%< Inc < -2.5%, considered No News Event;

·               < -2.5% decrease, considered Bad News Event.

In order to compare these sub categories, I further calculate average cumulative abnormal return for each category, within two broad portfolios of small and large cap companies.

Hypothesis testing

My hypothesis for all three portfolios, categorized by the type of event is:

H0: the AAR on the first day after the announcement are insignificantly different from 0.

H1: if the 0 is rejected the event has positively (Good News Portfolio), negatively (Bad news Portfolio) or did not affect at all (No news Portfolio) AAR across companies on the second day after the announcement of the Event.

To test the t-statistic, abnormal returns must be aggregated across all firms and the standard error has to be calculated. The average abnormal return across firms (AARt) for a sample of N firms at each time t within the event window is given by:

Where AR it = Abnormal return for stock i at time t

N = Number of events in the sample

The t-statistic for the null hypotheses that aggregated abnormal returns are equal to

zero is:

Where AAR t se = Standard error of AAR at time t

The standard error is calculated by dividing the standard deviation of the abnormal returns into the square root of the number of events in the sample. The t-test is a two tailed test at 5% significance level, with the critical value taken from the t-statistic with n-1 degrees of freedom.

In my case, as the number of events in each portfolio is equal to 1, t-stat will be calculated dividing the AARt by the SD.

In order to examine the magnitude of changes in share price (CAR 3 DAYS) and changes in earnings (Earnings Surprise), as well as, correlation between CAR 3 DAYS and Earnings Surprise, I build ordinary least squares regression model using E-View program.  

Finally, to analyse market reaction to non-earnings information and taking into the account that Earnings Surprise may not adequately explain the share price deviations, I include in my research a number of widely used factors that may affect on the stock market reaction, such as:

·               Changes in dividend policy (dividend per share ratio);

·               Share buy back;

·               Target-Bid Announcement;

·               Changes in Sales growth;

·               Changes in Leverage;

·               Changes in Gross Profit Margin;

·               Changes in EBIT;

·               Changes in Liquidity;

·               Changes in Corporate Governance;

·               R&D.

III. Test results and their interpretation

The earnings announcement sample illustrates the use of the abnormal and the cumulative abnormal returns. The results of this research shows a plot of the cumulative abnormal returns (CAR’s) over the entire 21 days of all three company categories, Good News Event, No News Event and Bad News Event. Âûíîñêà 3: Figure 2Ñêðóãëåííàÿ ïðÿìîóãîëüíàÿ âûíîñêà: Event dayÑêðóãëåííàÿ ïðÿìîóãîëüíàÿ âûíîñêà: Event dayThe observations support the hypothesis that earning announcements do indeed convey useful information for the valuation of Small Cap firms. The result demonstrates that the information contained in the good-news earnings announcement is useful in that if good-news has been detected, the market follows in the same direction. This is consistent with evidence found in the literature, Ball and Brown (1969). Bad-news findings do match with my expectations as well. However, the no-news findings follow a random walk, which also says that the market reacts to no change-in-earnings information and there are other factors which also influence the performance of the share price. For example, the Figure 2 shows even higher volatility in the reaction of the No-news portfolio returns, and Large Caps, being more transparent in their Corporate Governance submit dozens of other qualitative news to the market such as M&A activity, corporate restructuring etc.

At the same time, I have observed a high volatility of returns for my Small Caps after the announcement day, which is consistent with most academic studies and reflects their higher risk and lower liquidity.

Analyzing results of my test, I also observe that the evidence doesn’t support completely the hypothesis that earning announcements convey information for the valuation of Large Cap firms. The results demonstrate that the information contained in the good-news earnings announcement is useful in that if good-news has been detected, the market follows in the same direction with small overreaction at the beginning. Bad-news findings do not match with my expectations and no-news findings follow a random walk.

The test shows lower volatility of returns for Large Caps Good and Bad news after the announcement day. This is consistent with most academic studies and reflects lower risk and higher liquidity of the stocks.

Finally I find that Small Caps do react stronger to Good and Bad news announcements, while Large Caps are less responsive to these events. This is consistent result with my 3 hypothesis.

Small Caps T-test: The return is reflected in the t-test with a significant t-observed of +2.39 at day one for Good News Portfolio. The significance of the result means, rejecting the null hypothesis that the given event has no impact on security prices. Thus, I examine evidence that the market was surprised by the good-news of the company’s earnings announcements and has adjusted to the bad and no-news, which are both significant. Otherwise, the market expectations would have been included in the stock prices prior the announcement.

If the investor would have put his money 1 day prior the event into the good News portfolio, he would have achieved a 2.62% excess abnormal return over the FTSE All Shares Index after the event.

Large Caps T-test: The return is insignificant at day one for Good News Portfolio; though it follows the sign of the event. The insignificance of the result means, accepting the null hypothesis that the given event has no impact on security prices. The market was not surprised by the good-news of the company’s earnings announcements and has reacted positively to the Bad and No-news announcements, which are both significant.

To check, if proxies mentioned in Part I of this paper can explain the behaviour of my stock prices I have run a number of regressions:

·               Between CAR3 and Earnings Surprise and found R-squared of around 21% for Large Caps and R-squared of around 25% for Small Caps. This confirms the results of t-stat test and presence of other factors;

·               Unsatisfied by the explanatory power of this factor I include a number of other factors and get a maximum R-squared of around 46% for Large Caps and R-squared of around 40% for Small Caps which is still low.

Under and over reaction. Analysing this part of the research I find a clear higher over reaction for Good news portfolio of Small Caps, no excessive reaction for No news portfolio and less under-reaction for Bad news portfolio. Investors seem to be over optimistic for Good news and respond less to Bad news.

The results show under-reaction for Bad news and No news portfolios, which adapt lately and irrelevant behaviour of Good news portfolio. For my Small Caps portfolio Earning announcements are often one of the few sources of information and investors respond to these news behaving irrational. At the same time Large Caps produce more data and news as I have mentioned before and market seems to be prepared and this information is already incorporated in the share price. 

Ball, in his 1992 paper “The earnings-price anomaly”, looked at various reasons, provided by researchers to explain the persistence of the earnings-price anomaly (e.g. the drift in the market response to earnings announcements, implications of financial statements information for future earnings and abnormal returns). He found that most of them do not adequately explain the deviations. However, he accepted that the problems could come in bundles, which are difficult to estimate.

Interpretations of earnings/price anomalies:

1)            CAPM beta risk. Beta estimation error could be correlated with earnings.

2)            Transactions costs.

3)            Liquidity and trading mechanism effects. Increase in abnormal returns during the periods of illiquidity.

4)            Overstated t-statistics. Systematic understatement of standard errors of various statistics by researchers.

5)            Earnings variables proxies for expected returns. Either CAPM or the empirical market portfolio used in its implementation is misspecified, and the independent variables proxy for errors in estimating expected returns.

6)            Substantial information production costs or market inefficiency? Substantial costs of information acquisition and/or processing would be encountered in implementing the trading rules simulated by researchers.

7)            The inefficient-markets hypothesis. The market-inefficiency explanation requires prices to systematically provide unexploited pure-profit opportunities from using accounting information.

I consider most of the factors stated above to be relevant for my portfolio, which can explain deviations from the hypothesis.

Conclusion

The results revealed that my first hypothesis, positive earnings surprise should be followed by increase in the share price, can not be rejected for Small Caps portfolio which show positive and significant returns after the day of announcement of annual results and should be rejected for the Large Caps portfolio, which shows positive but insignificant CAR3.

Second hypothesis for the bad-news events can’t be rejected for Small Caps portfolio, for which the annual results are sometimes one of the few sources of information. Though, it can be interpreted differently for the Large Caps, which show positive and significant result. Investors will have incorporated the news provided in their security prices already. Over their whole investment period they take different sources like interim reports and other market data into consideration. The bullish stance has also prevailed during the examined period among investors, who were overoptimistic.

Third hypothesis that Small-cap firms react stronger to positive (negative) announcements than large-cap firms can’t be rejected as well and is well-shown on the graphs. Risk and liquidity parameters have probably affected higher volatility.

I examined the market over-reaction and under-reaction to positive (negative) earnings news, as well as, market reaction to non-earnings information and found that this seems to be the case for Small Caps portfolio and partly inconsistent in the case of Large Caps portfolio.

Since I found different factors, which can explain stock price behaviour, more work has to be done to better understand the strategic decision-making of the investors and to explain factors, which drive the performance of the share price.

References

1)            Ball and Brown, "An Empirical Evaluation of Accounting Income Numbers", Journal of Accounting Research, 1968, 6(2), pp. 159-78.

2)            Ball and Kothari, "Security Returns around Earnings Announcements”, Accounting Review, 1991, 66(4), pp. 718-38.

3)            Ball, “The Earnings-Price Anomaly”, Journal of Accounting and Economics, 1992, 15(2-3), pp. 319-45.

4)            Ball, Kothari and Ross, "Economic Determinants of the Relation between Earnings Changes and Stock Returns", Accounting Review, 1993, 68(3), pp. 622-38.

5)            Bodie, Kane and Marcus, Investments, 4th ed., Irwin McGraw Hill, 1999.

6)            Foster, Financial Statements Analysis, 2nd ed., Prentice Hall, 1986.

7)            Lasfer, “Research Project Management”, 2006, lecture notes.

8)            Lasfer, “Security Analysis”, 2006, lecture notes.

9)            Lev, “On the usefulness of Earnings and Earnings Research: Lessons and Directions from Two Decades of Empirical Research”, Journal of Accounting Research, 1989, pp.153-192.

10)       Ou and Penman, “Financial Statements Analysis and the Prediction of Stock Returns”, Journal of Accounting and Economics, 1989, pp. 295-329.

11)       Ou, “The Information Content of Nonearnings Accounting Numbers as Earnings Predictors”, Journal of Accounting Research, 1990, pp. 144-162.

12)       QI Sun, “Stock Price Reaction to Earnings Announcement Drift”, Working paper, School of Business Administration, University of Wisconsin-Miwaukee, 2005

13)       Winkelmann, “The Impact of Earning Announcements on Security Returns: An Analysis of German Mid-Cap Companies listed in the MDAX”, Dissertation, Cass Business School, 2002/

14)       Bloomberg database

15)       Datastream database

16)       Thompson Financial

17)       London Stock Exchange: www.londonstockexchange.com

18)       Companies’ websites