on the exclusion of assets from tests of the mean variance efficiency of the market portfolio this paper presents an analysis of the testability of the mean variance efficiency of a market index when the returns on some components of the index itself are not perfectly observable the results are basically not supportive of the notion that mean variance efficiency is testable on a subset of the assets bounding the market share of the missing asset and its expected return is not sufficient to produce a valid test when the variance of the missing asset is bounded and the amount of wealth that might be missing is small it is possible in principle to reject correctly the mean variance efficiency of a market index in his famous critique of the asset pricing theory tests roll 7 concludes that the only testable hypothesis associated with the generalized two parameter asset pricing model of black 1 is that the market portfolio is mean variance efficient it has been emphasized by ross 10 and roll 7 that the mean variance efficiency of the market portfolio is mathematically equivalent to a positive linear relation between expected returns and the betas calculated against such a portfolio roll 7 deduces that the theory capm is not testable unless the exact composition of the market portfolio is known and used in the tests this implies that the theory is not testable unless all individual assets are included in the sample errors of type one or two might occur when a market proxy is used instead of the true market portfolio even if the ex ante true expected returns and the covariance variance matrix of the returns on all the assets are used these errors are the result of the choice of the portfolio and as roll puts it even a small misspecification of the proxy s composition can lead to the wrong conclusion the market proxy might be mean variance efficient while the true market portfolio is not and vice versa in principle however there are cases in which the above two conditions are not both necessary to reject the theory one such exception presented by roll 7 is the case in which no totally positive portfolio is efficient if any totally positive market proxy is used a large sample would reject the null hypothesis unambiguously while the market portfolio identification problem constitutes a severe limitation to the testability of the theory the question of the mean variance efficiency of a particular market index with respect to a subset of assets is a typical problem of statistical inference the mean variance efficiency can be tested directly or by

market efficiency and insider trading new evidence that corporate insiders earn profits from stock trading does not surprise most financial economists but that outsiders can earn abnormal returns by using pub licly available insider trading data constitutes a serious exception to stock market efficiency the authors show that this anomaly conti nues to exist despite the publication of studies attesting to its exi stence they suggest that the anomalous profits to outsiders are a ma nifestation of the size and earnings price ratio effects controlling for these factors reduces outsider profits by half the additional a ssumption of a 2 percent transactions cost makes outsider profits zer o or negative insider profits after an assumed 2 percent transactio ns cost are a moderate 3 percent per annum for annual holding period s copyright 1988 by the university of chicago

discretionary accounting choices and the predictive ability of accruals with respect to future cash flows using a sample of restatement firms and a meet or beat model to classify firms as making discretionary accounting choices for opportunistic meet or beat op mb reasons we show that originally reported earnings and accrual components are less predictive of future cash flows relative to the restated numbers we find the opposite is true for firms classified as making discretionary accounting choices for non op mb reasons we consider a number of competing explanations for these latter results our findings are most consistent with the informational hypothesis weakly consistent with conservative motivated efficient contracting hypotheses but inconsistent with opportunistic contracting and misapplication errors of gaap explanations

insider trading as a signal of private information there is substantial evidence that insider trading is present around corporate announcements and that this insider trading is motivated by private information using real estate investment trusts that choose to reappraise themselves as our sample we establish that the appraisals contain information but find no market response to the public announcement of this information in these appraisals we consider two possible explanations for this inconsistency the first that the appraisal information is not highlighted in earnings reports and hence remains unobserved and the second that insiders trade on the appraisal information in the time that elapses between the appraisal and its public announcement we find strong support for the second hypothesis with insiders buying selling after they receive favorable unfavorable appraisal news especially for negative appraisals we also find that positive negative appraisals and net insider buying selling elicit significant positive negative abnormal returns during the appraisal period article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

implementation of nash bargaining solutions with non convexity abstract nash solutions for two player bargaining problems with non convexity are shown to be dictatorial selections of nash product maximizers in recent literature in this paper we show that these solutions are implementable as unique subgame perfect equilibrium payoff allocations of a sequential game

the effect of fast trading on price discovery and efficiency evidence from a betting exchange abstract we examine how the presence of fast traders impacts price discovery and efficiency in a real world setting i e courtsiding the activity of live betting from a tennis stadium this setting allows us to isolate the activity of fast acting traders who have a short term monopolistic access to important information with respect to other traders who trade based on delayed tv images using live tennis betting data combined with detailed point by point match data our results show that courtsider trading promotes quick price discovery and correctly incorporates new information into prices we estimate that a simple trading strategy yields a positive trading return to fast traders after the occurrence of important informational events

further international evidence on asset pricing the case of the spanish capital market abstract a multivariate framework is used in order to study the price formation of risky assets in the spanish capital market issues regarding the efficiency of the spanish value weighted stock market index the validity of equilibrium considerations the size effect and the nature of the return generating process during january are analyzed

multivariate tests of the zero beta capm abstract a cross sectional regression test csrt of the capm is developed and its connection to the hotelling t2 test of multivariate statistical analysis is explored algebraic relations between the csrt the likehood ratio test and the langrange multiplier test are derived and a useful small sample bound on the distribution function of the csrt is obtained an application of the csrt suggests that the crsp equally weighted index is inefficient but that the inefficiency is not explained by a firm size effect from february to december

implementing just and efficient decision making in an economy with one public good one private good and quasi linear utilities we explore decision making mechanisms to non cooperatively implement an efficient outcome by auctioning the leadership role among agents one implements egalitarianism namely the efficient outcome that distributes equally the surplus available from an a priori given status quo a refinement of this mechanism so called autioning the leadership with differentiated buds allows us to implement an efficient anonymous and neutral outcome it achieves egalitarianism above the vickrey clarke groves decision

exact arbitrage pricing and the minimum variance frontier the author examines the relationship between the arbitrage pricing theory of ross and mean variance analysis in particular conditions are derived on the vector of the factor risk premia that are equivalent to the existence of a strictly positively weighted portfolio on the minimum variance frontier also a sufficient condition is given under which the existence of a positive minimum variance portfolio of all the assets in the economy will imply the existence of a positive minimum variance portfolio on a subset this means that rejection of the hypothesis of the existence of a positive minimum variance portfolio on a subset satisfying this condition implies rejection for the whole set a growing body of literature explores the relationship between the arbitrage pricing theory apt of ross 13 14 and the mean variance model among the early work in this direction were the papers of chamberlain and rothschild 2 and chamberlain 1 these papers examine a sequence of economies and characterize the relationship in the limit between the mean and portfolio cost functionals and the minimum variance frontier chamberlain 1 also gives a condition under which exact arbitrage pricing will hold dybvig 4 and grinblatt and titman 7 examine equilibrium models in an apt context for a finite economy they derive sharp bounds on the deviation from exact arbitrage pricing recent papers by huberman kandel and stambaugh 9 and grinblatt and titman 8 explore the relationship between the apt and the mean variance model by studying portfolios that can be used as proxies for the factors and examining the relationship these portfolios bear to the minimum variance frontier these two papers also deal with equilibrium models in spite of the number and variety of equilibrium apt models the question of the pricing of factor risk in equilibrium remains largely unexplored this paper makes some progress in addressing that issue by looking at a given equilibrium restriction and studying the constraints it imposes on the vector of factor premia itself the most familiar equilibrium restriction we might study is the central implication of the capital asset pricing model capm that the market portfolio is efficient in particular no portfolio with the same expected return as the market portfolio has a smaller variance the restriction we actually study is weaker than

do insurers manipulate loss reserves to mask solvency problems abstract we report that insurance firms manage loss reserves to avoid violating certain test ratio bounds known as iris ratios that are used by regulators for solvency assessment in our sample almost two thirds of the firms that would violate four or more iris ratios successfully adjust reserves to reduce the reported number of violations to less than four this finding is significant because four violations usually trigger regulatory intervention our results indicate that non earnings goals are an important influence on discretionary accounting choice they also suggest that reserve manipulation can postpone needed regulatory intervention sometimes for an extended period

on multivariate tests of the capm abstract this paper evaluates the power of multivariate tests of the capital asset pricing model the results indicate that when employing an unspecified alternative hypothesis the ability of the tests to distinguish between the capm and other pricing models is poor an upper bound is derived for the distance the alternative distribution of the test statistic can be from the null distribution when the deviations from the capm are due to missing factors this upper bound explains the low power of the tests

insiders sales under rule 10b5 1 plans and meeting or beating earnings expectations we find that firms with insider sales executed under rule 10b5 1 plans exhibit a higher likelihood of meeting or beating analysts earnings expectations mbe this relation between mbe and plan sales is more pronounced for the plan sales of chief executive officers ceos and chief financial officers cfos and is nonexistent for other key insiders the market reactions to firms that successfully meet or beat expectations are relatively positive compared with their peers that fail to do so one interpretation of our results is that ceos and cfos who sell under these plans may be more likely to engage in strategic behavior to meet or beat expectations in an effort to maximize their proceeds from plan sales however readers should exercise caution in making inferences because the potential presence of limit order transactions makes it difficult to unambiguously determine the direction of causality of the relation we document this paper was accepted by mary barth accounting

insider trades and demand by institutional and individual investors there is a strong inverse relation between insider trading and institutional demand the same quarter and over the previous year our analysis suggests a combination of factors contribute to this relation first institutional investors are more likely to provide the liquidity necessary for insiders to trade second insiders are more likely to buy low valuation and low lag return stocks while institutions are attracted to the opposite security characteristics last the results are consistent with the hypothesis that insiders are more likely to view their securities as overvalued undervalued following a period when institutions were net buyers sellers the author 2010 published by oxford university press on behalf of the society for financial studies all rights reserved for permissions please e mail journals permissions oxfordjournals org oxford university press

noncooperative foundations of the area monotonic solution given a finite set of alternatives players alternate making offers player 1 offers some alternative that 2 can accept or veto if 2 accepts it is enforced and the game ends otherwise 2 makes a counteroffer among the remaining alternatives and so on if all alternatives are vetoed a disagreement alternative is enforced first we characterize the unique outcome of any subgame perfect equilibrium of this game then we show that this outcome converges to the area monotonic solution if the alternatives are uniformly distributed over the bargaining set and as the number of alternatives tends to infinity

what insiders know about future earnings and how they use it evidence from insider trades abstract this paper provides evidence that insiders possess and trade upon knowledge of specific and economically significant forthcoming accounting disclosures as long as 2 years prior to the disclosure stock sales by insiders increase three to nine quarters prior to a break in a string of consecutive increases in quarterly earnings insider stock sales are greater for growth firms before a longer period of declining earnings and when the earnings decline at the break is greater consistent with avoiding an established legal jeopardy there is little abnormal selling in the two quarters immediately prior to the break

the likelihood ratio test statistic of mean variance efficiency without a riskless asset abstract the question whether a given porfolio is mean variance efficient is a basic problem of investment analysis mean variance efficiency is also the basis of the capital asset pricing model this paper presents the explicit form of the likelihood ratio test of the hypothesis that a given portfolio or a particular market index is ex ante mean variance efficient in the case where there is no riskless asset geometric relations are illustrated to provide intuition about the constrained maximum likelihood estimators and the test statistic and two simple economic interpretations of the test are given

on the exclusion of assets from tests of the mean variance efficiency of the market portfolio an extension this paper extends kandel s 3 analysis of the testability of the mean variance efficiency of a market index when the return on some component of the index is not perfectly observable in addition to information about the mean and variance of the missing asset considered by kandel we explore the usefulness of information about the beta of the missing asset on the observed sub portfolio in an economy with a riskless asset the results are somewhat more supportive of the notion that mean variance efficiency is testable on a subset of the assets in his important critique of tests of the capital asset pricing model roll 4 emphasizes that empirical results obtained with market proxies need not be indicative of the results that would be obtained in testing the efficiency of the true market portfolio were it observable more recently kandel 3 has analyzed the testability of the mean variance efficiency of a market portfolio when the return on some component of the portfolio is not perfectly observable but partial information about its characteristics is available he finds that knowledge of the market share and expected return of the missing asset is not sufficient to permit a test however bounding the variance of return on the missing asset does make it possible in principle to correctly reject the efficiency of the portfolio provided that the market share of the missing asset is not too large building on the analytical framework established by kandel we explore the value of information about the riskless rate of return and the covariance betwen the return on the missing asset and the observed sub portfolio given a riskless asset the question we address is whether the unobservable market portfolio of risky assets is equal to the tangency portfolio of the efficient frontier we find that knowledge of the market share and expected return of the missing asset is still not sufficient to permit a test of this more restrictive efficiency condition as in the no riskless asset case given a bound on the variance of the missing asset it is sometimes possible to correctly infer that the unobserved portfolio is inefficient this occurs when the market share of the missing asset or the variance of its return is small and the sub portfolio is sufficiently far from the linear

potential performance and tests of portfolio efficiency abstract the potential performance of an asset set may be obtained by choosing the portfolio proportions to maximize the sharpe 1966 performance measure if a portfolio has a sharpe measure equivalent to the potential performance of the underlying set of assets then it is efficient multivariate statistical procedures for comparing potential performance and testing portfolio efficiency are developed and then evaluated using simulations two likelihood ratio statistics are then used to compare stock and bond indices against sets of 20 and 40 portfolios the procedures are also compared to the gibbons 1982 methodology for testing financial models

factor pricing in a finite economy abstract prior theoretical derivations of the arbitrage pricing theory apt bound an aggregate measure of the deviation of mean asset returns from that predicted by a linear pricing equation it is conceivable given this bound that some assets might be badly mispriced by the model in this paper a more intuitive derivation of the factor pricing equation is presented which describes the deviation on an asset by asset basis the deviation is shown to be small for assets in a realistic finite economy and is arbitrarily close to zero for those assets with arbitrarily small size relative to aggregate wealth it follows that the linear pricing equation provides a good approximation for the mean returns of all traded assets

multivariate proxies and asset pricing relations abstract a framework is developed in which inferences can be made about the validity of an equilibrium asset pricing relation even though the central aggregate in this relation is unobservable a multivariate proxy for the true market portfolio consisting of an equal weighted stock index and a long term government bond index is employed in an investigation of the sharpe lintner capm the empirical evidence suggests that we can reject the joint hypothesis that a capm is valid and b multiple correlation between the true market portfolio and proxy assets exceeds 0 7 connections to the equilibrium factor pricing literature are also explored

the analytics of performance measurement using a security market line security market line sml analysis while an important tool has never been fully justified from a theoretical standpoint assuming symmetric information and an inefficient index we show that sml analysis can be grossly misleading since in general efficient and inefficient portfolios can plot above and below the sml on a more positive note if sml analysis uses the return on a marketed riskless asset for the zero beta rate efficient portfolios must plot above the sml nonetheless arbitrarily inefficient portfolios also plot above the sml mean variance theory is still the premier theory in finance it continues to survive theoretical criticism and empirical rejection2 and it does so in no small part because of the popularity of using deviations from the security market line sml in performance measurement of portfolio managers and in event studies of the price impact of information the sml is the relationship between risk and return predicted by the mean variance model namely that risk as measured by beta and expected return are linearly related sml analysis interprets deviations in expected return from the sml as abnormal returns above or below what is appropriate or warranted for the amount of risk taken on however in the mean variance model all assets and portfolios lie on the sml ex ante and any ex post deviations from the sml are attributable solely to statistical measurement errors it is for this reason that roll 22 25 has argued that justification for sml analysis must lie outside the original mean variance model the purpose of this paper and its companion paper dybvig and ross 8 is to study whether sml analysis is valid in several plausible theoretical frameworks i e whether theory justifies intuition specifically in this article we examine the validity of using sml analysis when the index portfolio is inefficient in the companion paper we look at performance yale school of management the authors appreciate especially helpful comments from michael brennan gregory conner mike gibbons mark grinblatt jon ingersoll paul pfeiderer and richard roll the first author is grateful for support under the batterymarch fellowship program and the second author is grateful for support from the national science foundation this paper and its campanion paper dybvig and ross 8 evolved from dybvig and ross 7

subgame perfect implementation of bargaining solutions abstract this paper provides simple four stage game forms that fully implement a large class of two person bargaining solutions in subgame perfect equilibrium the solutions that can be implemented by our game forms are those that maximize a monotonic and quasi concave function of utilities after normalizing each agent s utility function so that the maximum utility is 1 and the utility of the disagreement outcome is 0 this class of solutions includes the nash kalai smorodinsky and relative utilitarian solutions the game forms have a structure of alternating offers and contain no integer device

nash demand game and the kalai smorodinsky solution we introduce two new variations on the nash demand game in one as in all past variants of nash demand games the nash bargaining solution is the equilibrium outcome the other demand game allows for probabilistic continuation in cases of infeasible joint demands specifically with probability 1 p the game terminates and the players receive their disagreement payoffs but with probability p the game continues to a second stage in which one of the two incompatible demands is randomly selected and implemented surprisingly the kalai smorodinsky solution is always the outcome of the most robust equilibrium of this game moreover ranking other solution concepts is impossible

overreaction and insider trading evidence from growth and value portfolios insider transactions are not random across growth and value stocks we find that insider buying climbs as stocks change from growth to value categories insider buying also is greater after low stock returns and lower after high stock returns these findings are consistent with a version of overreaction which says that prices of value stocks tend to lie below fundamental values and prices of growth stocks tend to lie above fundamental values do market prices reflect investor overreaction 1 the purpose of this paper is to provide evidence on this question however new evidence is unlikely to change many minds if the findings depend on the newly controversial capital asset pricing model capm or multifactor models or if they involve datasnooping 2 we bypass these problems by not using capm or a benchmark model and by examining a new set of data we measure insider buying and selling in stocks that are ranked by measures such as the ratio of cash flow per share to price per share cf p 3 current practice refers to stocks with low cf p as growth stocks and to stocks with high cf p as value stocks we examine the direction of insider trades along the growth value spectrum to see if they are consistent with attempts to profit from market overreaction by overreaction we mean price movements that predictably reverse this experiment does not require an asset pricing model because we do not examine the returns accruing to insider trades 4

information sales and insider trading with long lived information fundamental information resembles in many respects a durable good hence the eects of its incorporation into stock prices depend on who is the agent controlling its flow similarly to a durable goods monopolist a monopolistic analyst selling information intertemporally competes against herself this forces her to partially relinquish control over the information flow to traders conversely an insider solves the intertemporal competition problem through vertical integration thus exerting a tighter control over the flow of information comparing market patterns i show that a dynamic market where information is provided by an analyst is thicker and more informative than one where an insider trades

positively weighted portfolios on the minimum variance frontier duality theory is employed to provide necessary and sufficient conditions for portfolios on the minimum variance frontier to have positive investment proportions in all assets these conditions involve the feasibility of portfolios that have non negative correlation with all assets and positive correlation with at least one using these results several qualitative results concerning the signs of investment proportions in efficient portfolios are proved it is argued that the conditions that ensure all positive weights in efficient portfolios are intuitively compelling and are not unique to the capm with large numbers of assets however the signs of weights in minimum variance portfolios can be very sensitive to slight departures from these conditions due to for example sampling error the behavior of the minimum variance frontier is of general concern to portfolio theory and plays a central role in the study of asset pricing an unresolved question in the theory of the minimum variance frontier involves when it will contain portfolios with positive weights on all assets this paper addresses that question we show that the conditions that ensure positive investment proportions in efficient portfolios have by farkas lemma a simple dual this dual or alternative system of inequalities puts conditions directly on the variances covariances and means of the returns and these conditions can be interpreted intuitively this contrasts with simply considering the first order conditions for variance minimization since these involve the inverted covariance matrix with a large number of assets it can be difficult to translate one s intuitive sense about how assets covary into statements about the inverse of the covariance matrix the duality conditions we derive involve the existence of portfolios that are positively or negatively correlated with all assets indeed we show that a necessary and sufficient condition for no portfolio on the frontier to have all positive weights is the feasibility of an arbitrage or hedge portfolio with weights that sum to zero that has an expected payoff of zero and has non negative correlation with all assets the duality conditions also make it easy to construct examples of the types of covariability that permit or preclude positive investment proportions on all assets in frontier portfolios there are at least three apparent reasons for interest in the signs of weights

bargaining and the value of money abstract search models of monetary exchange have typically relied on nash 1950 the bargaining problem econometrica 18 155 162 bargaining or strategic games that yield an equivalent outcome to determine the terms of trade by considering alternative axiomatic bargaining solutions in a search model with divisible money we show that the properties of the bargaining solutions do matter both qualitatively and quantitatively for questions of first degree importance in monetary economics such as i the efficiency of monetary equilibrium ii the optimality of the friedman rule and iii the welfare cost of inflation

fair allocation when players preferences are unknown suppose an arbitrator needs to allocate an asset among two players whose claims on the asset are incompatible the allocation outcome is said to be fair if the arbitrator awards an outcome that brings the same utility payoff to the two players whenever the two players claims are symmetric and the allocation set is symmetric in conjunction with other natural axioms this fairness requirement implies a unique allocation outcome for any claims problem we propose a mechanism which can be used by the arbitrator to implement this allocation outcome even when the players preferences are unknown to the arbitrator jel c78 d63 j52

robustness of intermediate agreements and bargaining solutions abstract most real life bargaining is resolved gradually during this process parties reach intermediate agreements these intermediate agreements serve as disagreement points in subsequent rounds we identify robustness criteria which are satisfied by three prominent bargaining solutions the nash proportional and as a special case to the egalitarian solution and discrete raiffa solutions we show that the robustness of intermediate agreements plus additional well known and plausible axioms provide novel axiomatizations of the above mentioned solutions hence we provide a unified framework for comparing these solutions bargaining theories

an international capm for bonds and equities abstract previous empirical studies of international capm models have not found much supporting evidence in this paper we suggest reasons why this might have happened and perform new tests using improved models and data a range of monthly capm models are estimated for 1973 1987 for aggretate equities and bonds in germany japan the us and uk the models are an improvement on earlier work in that we integrate equity markets into the analysis instead of focusing exclusively on government bond stocks and we carefully measure the rates of return for both bonds and equities in particular bond returns reflect changes in the price of bonds as well as coupons despite this wider portfolio and the introduction of arch effects in the conditional covariance matrix of errors our model still yields unlikely estimates of the coefficient of relative risk aversion and provides very little explanatory power for expected relative rates of return correcting the icapm for these major deficiencies does not reverse earlier conclusions in the literature a close examination of the residuals of the estimated equations suggest that garch models are not required for our new data set jel fh

ceo stock option awards and the timing of corporate voluntary disclosures abstract we investigate whether ceos manage the timing of their voluntary disclosures around stock option awards we conjecture that ceos manage investors expectations around award dates by delaying good news and rushing forward bad news for a sample of 2 039 ceo option awards by 572 firms with fixed award schedules we document changes in share prices and analyst earnings forecasts around option awards that are consistent with our conjecture we also provide more direct evidence based on management earnings forecasts issued prior to award dates our findings suggest that ceos make opportunistic voluntary disclosure decisions that maximize their stock option compensation

earnings management to avoid earnings decreases and losses this paper provides evidence that firms manage reported earnings to avoid earnings decreases and losses specifically in cross sectional distributions of earnings changes and earnings we lind unusually low frequencies of small decreases in earnings and small losscs and unusually high frequencies of small increases in earnings and small positive income we find evidence that two components of earnings cash flow from operations and changes in working capital are used to achieve increases in earnings we present two theories based on stakeholder use of information processing heuristics and prospect theory about the motivation for avoidance of earnings decreases and losses

decoding inside information exploiting the fact that insiders trade for a variety of reasons we show that there is predictable identifiable routine insider trading that is not informative about firms futures a portfolio strategy that focuses solely on the remaining opportunistic traders yields value weighted abnormal returns of 82 basis points per month while abnormal returns associated with routine traders are essentially zero the most informed opportunistic traders are local nonexecutive insiders from geographically concentrated poorly governed firms opportunistic traders are significantly more likely to have sec enforcement action taken against them and reduce trading following waves of sec insider trading enforcement

private information in executive stock option trades evidence of insider trading in the uk uk executives stock option exercises and associated sell decisions are motivated by private inside information executives use their inside information to lock in short term gains and to sell stock acquired prior to negative abnormal stock returns this informed trading is robust to the alternative factors that might motivate the exercise of executive stock options including option moneyness and value of exercise we suggest that the disparity in informed trading between us and uk executives option trades is related to important differences in the proportion of executive remuneration linked to options the regulation of options and the taxation of option gains

implementing the kalai smorodinsky bargaining solution the bargaining game is proposed where the agents bid fractions of dictatorship that are used by all non winners of the auction to threaten acceptance of the winner s proposal that procedure non cooperatively implements the kalai smorodinsky bargaining solution

on correlations and inferences about mean variance efficiency a framework is presented for investigating the mean variance efficiency of an unobservable portfolio based on its correlation with a proxy portfolio a sensitivity analysis derives the highest correlation between the proxy and a portfolio that reverses the inference of a test of sharpe lintner tangency for example the maximum correlation between the value weighted nyse amex portfolio and a portfolio inferred tangent ranges from 0 76 to 0 48 we also test whether the correlation between the proxy and the tangent portfolio exceeds a given level this hypothesis is often rejected for the nyse amex proxy at a correlation of 0 7

consistency in meeting or beating earnings expectations and management earnings forecasts abstract this paper provides evidence that firms that have consistently met or beaten analysts earnings expectations mbe provide more frequent bad news management forecasts than firms with no established string of mbe particularly when existing analyst forecasts are optimistic this suggests that firms with a consistent mbe record are more likely to guide analysts expectations downward to avoid breaking the consistency subsequent analyst forecast revisions following bad news management forecasts issued by these firms are dampened implying that analysts suspect that these forecasts may be opportunistic the relation between management forecasts and mbe consistency is stronger after regulation fd

an explicit bound on individual assets deviations from apt pricing in a finite economy abstract ross s arbitrage pricing theory apt is a tractible and reasonable alternative to the mean variance model nonetheless understanding of the theory has been obscured by the complexity of the sequence economy models used for motivation by contrast we give a simple and direct derivation of the apt in a finite economy using an explicit bound on the deviations from apt prices across assets a coarse calculation shows that theoretical deviations from apt pricing are negligible in our economy

the conditional auction mechanism for sharing a surplus a first bid auction to allocate the leadership role is used to choose a public decision and a balanced set of transfers the mechanism is shown to implement an equal sharing of the surplus above the average utility level at the equilibrium an agent s message reveals the other agent s utility when only two players are involved and the exact value of the joint surplus a variety of other contexts allow for the construction of similar auction like mechanisms displaying the same mirror image effect

yes the apt is testable the arbitrage pricing theory apt has been proposed as an alternative to the meanvariance capital asset pricing model capm this paper considers the testability of the apt and points out the irrelevance for testing of the approximation error we refute shanken s objections including his assertion that roll s critique of the capm is applicable to the apt we also explain the testability of the apt on subsets and we explore the relationship between the apt and the capm the arbitrage pricing theory apt has been the subject of extensive research efforts since it was introduced by ross 36 37 the research has included theoretical papers and a growing empirical literature 2 nonetheless there seems to be some confusion in the literature about the relation between the theoretical underpinnings of the apt and its empirical tests this paper is an attempt to alleviate the confusion to illustrate the issues and to provide a focus section i of this paper is devoted to examining and refuting some points raised in shanken 40 which considers the testability of the apt the underlying premise of the apt is that asset returns ri are generated by a factor model of the form

corporate bankruptcy and insider trading the authors document significant sales by the insiders of firms filing bankruptcy petitions prior to the filing date they also find that selling is more intense for top executives and officers and that insiders in general systematically sell stock before prices fall and buy stock after prices have fallen although this trading pattern may simply reflect an implicit compensation arrangement between insiders and stockholders the significant sell off does raise potential questions regarding managements incentives to maximize shareholder wealth throughout the chapter 11 process copyright 1997 by university of chicago press

attracting attention in a limited attention world exploring the causes and consequences of extreme positive earnings surprises we investigate why extreme positive earnings surprises occur and the consequences of these events we posit that managers know before analysts when extremely good earnings news is developing but can have incentives to allow the earnings news to surprise the market at the earnings announcement in particular managers can use an extreme positive earnings surprise to attract investor attention when they believe their stock is neglected and future performance is expected to be strong analysts who must allocate scarce resources across many firms can also be inattentive and miss signals that suggest good performance is going to be announced using various proxies for extreme positive earnings surprises management expectations for future performance and desire for attention and analyst neglect we find evidence that an extreme positive earnings surprise is a predictable event these findings are incremental to controlling for a firm s information environment earnings volatility and operating leverage finally we show that extreme positive earnings surprises are a successful method for attracting attention with significant increases in the number of institutional owners the number of analysts and trading volume during the subsequent three years this paper was accepted by mary barth accounting

block holding and keiretsu in japan the effects of capital markets liberalization measures on the stock market abstract long term block holding among large industrial corporations and financial institutions is prevalent in japan little is known about the implications of such business practice on portfolio returns we document the portfolio relationships of parent firms sub firms and specific industry portfolios and we hypothesize that these relationships have changed substantially in japan using certain measures for evaluating portfolios and mean variance spanning we test the hypothesis our empirical results suggest that market efficiency and integration of the japanese stock market may have been greatly enhanced by the japanese government s capital markets liberalization measures implemented in the 1970s and early 1980s

multi beta capm or equilibrium apt a reply in their influential empirical paper roll and ross 11 state we think that in many discussions of the capm scholars were actually thinking of the apt and of process 1 the factor model with just a single factor in light of recent developments in the asset pricing literature i think it can now meaningfully be suggested that in many discussions of the apt scholars may have actually been thinking of a multi beta interpretation of the capm indeed much can be said in support of each of these perspectives for a single paradigm is emerging which integrates fundamental aspects of both the capm and the apt broadly speaking the equilibrium capm paradigm emphasizes the role of covariance between asset returns and an endogenous preference based aggregate while the arbitrage apt paradigm focuses on the covariance between asset returns and factors in the return generating process the emerging equilibrium factor paradigm encompasses each of these relations as well as a third covariance between the factors and the equilibrium aggregate my thesis in shanken 17 was that i the arbitrage paradigm has not produced a refutable hypothesis and that ii recognition of the role of the factor aggregate covariance relation appears to be essential if positive economic significance is to be attributed to asset pricing empirical work dybvig and ross d r attempt to resolve the empirical indeterminacy of the arbitrage paradigm by appealing to the condition that residual variance should not be too large i explain in section ii that this condition is inherently ambiguous from an empirical perspective and does not permit the formulation of a precise testable implication the equilibrium factor models which d r discuss do yield testable restrictions on parameters in the return generating process however consistent with my second point above these restrictions involve joint hypotheses that cannot be verified without observing the entire universe of assets thus contrary to their claim considerations similar to those in roll s 10 critique are indeed relevant to the testing of these models this and other similarities between the equilibrium apt and the capm are discussed in section iii i begin by clarifying some basic terminology