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

expected inflation and the real rates of interest on taxable and tax exempt bonds this paper analyzes the impact of inflation on rates of return on taxable corporate bonds and tax exempt municipal bonds the paper considers a differential tax system where the tax rate depen ds on both the identity of the investor and the source of income it also consid ers the possibility that inflation may induce investors to switch from holding one asset to holding another it is demonstrated that while inflation should increase the pre personal tax real rate of interest on taxable bonds it should reduce the real rate of interest on tax exempt bonds copyright 1987 by ohio state university press

the fisher equation controversy a reconciliation of contradictory results where r is the real interest rate assuming that the real interest rate is constant the above equation yields the fisherian prediction of co plete adjustment di dit 1 fisher s empirical findings however indicated only a partial adjustment of nominal interest rates to inflation expectations the contradiction between fisher s theoretical and e pirical findings was confounded further by mundell 11 and tobin 19 who provided theoretical results consistent with fisher s empirical finding of partial adjustment the fascination with deriving theoretical results consistent with fisher s empirical finding continues sargent 14 15 16 visco 20 and fried and howitt 8 have all attempted to provide theoretical justification for the partial adjustment result

the pricing of currency risk in japan abstract previous work on the pricing of exchange rate risk has primarily focused on us firms and surprisingly found stock returns were not significantly affected by exchange rate fluctuations in this paper we conduct an in depth investigation that examines whether exchange rate risk is priced in the equity market of japan using an intertemporal asset pricing testing procedure that allows risk premia to change through time in response to changes in macroeconomic conditions our multiperiod asset pricing tests show that the foreign exchange rate risk premium is a significant component of japanese stock returns specifically the results suggest that currency risk exposure commands a significant risk premium for multinationals and high exporting japanese firms the currency risk factor is found to be less influential in explaining the behavior of average returns for low exporting and domestic firms however it is shown to exhibit large return volatility that is likely to be perceived by investors who wish to control portfolio risk as an important underlying source of risk furthermore japanese stock returns are found to be related to the relative distress and size factors above and beyond the covariation explained by the currency risk factor

measuring the pricing error of the arbitrage pricing theory this article provides an exact bayesian frame work for analyzing the arbitrage pricing the ory apt based on the gibbs sampler we show how to obtain the exact posterior distributions for functions of interest in the factor model in particular we propose a measure of the apt pricing deviations and obtain its exact posterior distribution using monthly portfolio returns grouped by industry and market capitalization we find that there is little improvement in reduc ing the pricing errors by including more factors beyond the first one as an important extension of the asset pricing model of sharpe 1964 and lintner 196 5 ross 1976 1977 derived the arbitrage pricing theory apt which addresses a fundamental problem in finance to char acterize the expected return on a security the apt implies that the expected return is approximately a

decoupled farm program payments are really decoupled the theory lump sum transfers to farmers are commonly believed to affect the production choices of farmers in the presence of risk and uncertainty this paper shows that if farmers have off farm investment and employment opportunities production decisions are decoupled from lump sum subsidies in the presence of risk and uncertainty our results are reconciled with existing results by showing that previously identified production adjustments are portfolio adjustments

nonpecuniary benefits to farming implications for supply response to decoupled payments we develop a household model wherein farmers allocate labor to maximize utility from leisure consumption and nonpecuniary benefits from farming the model shows that farmers with decreasing marginal utility of income respond to higher decoupled payments by decreasing off farm labor and increasing farm labor resulting in greater agricultural output we then estimate the difference between farm and off farm returns to labor using data from three nationally representative farm household surveys the finding of a large on farm off farm wage differential provides compelling evidence of substantial nonpecuniary benefits from farming

do decoupled payments affect investment financing constraints evidence from irish agriculture abstract this paper empirically tests whether decoupled subsidies decrease investment financing constraints faced by farms using a panel dataset from ireland over the period 2005 2010 we test whether the cap decoupled subsidy payments reduce credit constraints by altering the risk profile of farm earnings we test for financing constraints in a neoclassical q model using investment cash flow sensitivities our econometric methodology controls for censoring heterogeneity and endogeneity we find that decoupled subsidies do reduce credit constraints the effect is greater for farms that face higher constraints dairy farmers and younger farms this evidence suggests that over and above the effect on production indicated in previous research decoupling affects farm investment through financial channels

using generalized method of moments to test mean variance efficiency this paper develops tests of unconditional mean variance efflciency under weak distributional assumptions using a generalized method of moments framework these tests are potentially more robust than commonly employed tests which rely on the assumption that asset returns are normally distributed and temporarily i i d using returns for size based portfolios from 1926 to 1988 we show that the conclusion concerning the mean variance effilciency of market indexes can be sensitive to the test considered the application of multivariate statistical techniques in financial economics has become common practice in recent years much of the development has been in the area of testing asset pricing models the assumption that asset returns follow a time invariant multivariate normal distribution permits tests of restrictions on model parameters in a pooled time series cross section framework these tests can be interpreted as tests of the mean variance efficiency of a portfolio or combination of portfolios gibbons 1982 jobson and korkie 1982 stambaugh 1982 shanken 1985 1987 kandel and stambaugh 1987 mackinlay 1987 and gibbons ross and shanken 1989 are examples of work presenting multivariate tests of the capital asset pricing model connor and korajczyk 1988 and lehmann and modest 1988 present multivariate tests of the arbitrage pricing model breeden gibbons and litzenberger 1989 present multivariate tests of the consumption based capm although these papers assume the normality of asset returns little analysis has been conducted to understand the sensitivity of the inferences to violations of this assumption 2 3

the mean variance efficiency of benchmark portfolios uk evidence abstract this paper examines the ex ante mean variance efficiency of four alternative benchmark portfolios within a uk context each of the benchmark portfolios is shown to be mean variance inefficient over the period january 1980 to december 1989 additionally the gibbons et al test statistic of efficiency appears to be fairly robust to violations in the distributional assumptions gibbons m r s a ross and j shanken 1989 test of the efficiency of a given portfolio econometrica 57 1121 1152

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

some results in the theory of arbitrage pricing this paper derives a stronger version of huberman s recent preference free pricing theorem this pricing result relates the expected return on an asset to its factor responses and the covariance structure of the residuals from a linear factor model it must characterize any infinite asset economy in which no arbitrage opportunities are present whether or not the factor model has uncorrelated residuals this result provides the intuition for the role of residual risk in the pricing model and eliminates some classes of arbitrage opportunities still present under huberman s bound some applications to empirical tests and performance measurement are also discussed the arbitrage pricing theory is one of several financial pricing models which attempts to explain the cross sectional variation in expected returns on assets in certain respects it is similar to the capital asset pricing model but there are both substantive and subtle differences one of the key advantages of the apt is that it derives a simple linear pricing relation approximating that in the capm without some of the latter s objectionable assumptions perhaps the key disadvantage of the apt is that it provides no clues as to what might be important factors nor as to how to interpret the factor premiums which appear in the pricing equation this paper serves several purposes after reviewing the linear factor model formulation in section i it derives in section ii a stronger version of huberman s 9 recent preference free pricing theorem this pricing result relates the expected return on an asset to its factor responses and the covariance structure of the residuals this relation must characterize any infinite asset economy in which no arbitrage opportunities are present whether or not a linear factor model with uncorrelated residuals is the appropriate returns generating mechanism section iii specializes this result by eliminating the effects of residual covariances and compares the results here to those of previous apt models when applied to the standard linear factor model with uncorrelated residuals this new pricing bound eliminates arbitrage opportunities which remain under huberman s bound this result also provides for the first time the intuition for the role of residual risk in the approximate pricing relation section v provides an interpretation of the factor premiums and gives a valid asset pricing model interpretation to the apt which is consistent with merton s

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

direct price controls as a source of instability in the interest rate inflation rate relationship abstract we hypothesize that an efficient capital market is more concerned with effective inflation rates which investors experience than official ones which econometricians observe and that direct consumer goods price controls are likely to result in disparity between the two consequently direct price controls are also likely to affect the interest measured inflation rate relationship we ropose a dummy variable approach which enables us to explore empirically the effects of such controls on the interest inflation rate relationship in the context of dwyer s 1981 model using euro rates and inflation rates of the respective countries we explore the impact of the control programmes imposed in the 1970 s by governments of the united states canada and france france

small sample tests of portfolio efficiency abstract this paper presents an eigenvalue test of the efficiency of a portfolio when there is no riskless asset complementing the test of gibbons ross and shanken 1989 besides optimal upper and lower bounds an easily implented numerical method is provided for computing the exact p value our approach makes it possible to draw statistical inferences on the efficiency of a given portfolio both in the context of the zero beta capm and with respect to other linear pricing models as an application using monthly data for every consecutive five year period from 1926 to 1986 we reject the efficiency of the crsp value weighted index for most periods

nonnormalities and tests of asset pricing theories the robustness of the multivariate test of gibbons ross and shanken 1986 to nonnormalities in the residual covariance matrix is examined after considering the relative performance of various tests of normality simulation techniques are used to determine the effects of nonnormalities on the multivariate test it is found that where the sample nonnormalities are severe the size and or power of the test can be seriously misstated however it is also shown that these extreme sample values may overestimate the population parameters hence we conclude that the multivariate test is reasonably robust with respect to typical levels of nonnormality in traditional hypothesis testing a nonrandom test maps the values of a random variable into a sample space dichotomized into regions where a hypothesis is either accepted or rejected there are three possible outcomes from this process 1 a correct decision 2 a false rejection type i error or 3 failure to reject the hypothesis when it is false type ii error of the latter two types of error an error of the first kind is usually considered less desirable so typically a level of significance is selected with low probability of type i error e g 0 05 or 0 01 and a test is chosen so as to maximize power minimize probability of type ii error for the specified level of type i error knowledge of the relative level of these two errors is critical in assimilating the results of an experiment for example if the power of a test is equal to its significance level i e a weak test rejection of the null contains zero information 2 additionally in constructing parametric tests of hypotheses it is necessary to assume some distribution for the underlying data consequently when using parametric tests rejection of the null is only equivalent to rejection of at least one of the underlying hypotheses i e the null hypothesis or the distributional assumption interestingly the size significance level and power of procedures used to test

the effects of policy expectations on crop supply with an application to base updating we develop a dynamic model to assess the effects of policy expectations on crop supply and illustrate the approach with estimates of the effects of base updating in u s crop programs for corn and soybeans in the corn belt the effect of base updating is relatively small because relevant crop alternatives are subject to similar policies and the alternatives are substitutes in production increasing acreage of one program crop to capture future payments from base updating reduces future payments from the alternative crop we also use our model to assess the effect of base updating on acreage response to prices

inflation taxation and interest rates this paper demonstrates that the response of nominal interest rates to changes in inflationary expectations should lie between that predicted by the fisher and darby effects the exact nature of the response will depend on the relative size of the income and capital gains tax rates and the relative size of the derivatives of investment and savings to their respective after tax real rates the other major conclusion of this paper is that capital gains taxation offsets the negative effect on investment produced by treating depreciation on a historic rather than a replacement cost basis in the 1960s and early 1970s the economics profession and the financial community increasingly accepted irving fisher s analysis of the effect of changes in anticipated inflation on the rate of interest in the last several years darby 4 and feldstein 5 have elaborated fisher s theory and have arrived at the conclusion that in a world with taxes an increase in inflationary expectations should result in a more than proportional increase in the nominal rate of interest since investors base their investing and saving decisions on the after tax and not the pretax expected consequences of their actions darby 4 has argued that if income taxes are proportional at rate t and interest receipts are taxable and interest payments are tax deductible the real after tax interest rate is

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

fiscal policy driven bond risk premia abstract fiscal policy matters for bond risk premia empirically government spending level and uncertainty predict bond excess returns as well as term structure level and slope movements shocks to government spending level and uncertainty are also priced in the cross section of bond and stock portfolios theoretically government spending level shocks raise inflation when marginal utility is high thus generating positive inflation risk premia term structure level effect uncertainty shocks steepen the yield curve slope effect producing positive term premia these effects are consistent with evidence from a structural vector autoregression asset pricing tests using model simulated data corroborate our empirical findings

a critical reexamination of the empirical evidence on the arbitrage pricing theory this paper demonstrates that the roll and ross rr and other previously published tests of the apt are subject to several basic limitations there is a general nonequivalence of factor analyzing small groups of securities and factor analyzing a group of securities sufficiently large for the apt model to hold it is found that as one increases the number of securities the number of factors determined increases this increase in the number of factors with larger groups of securities cannot readily be explained by a distinction between priced and nonpriced risk factors as it is impermissible to carry out tests on whether a given risk factor is priced using factor analytic procedures the apt model as exposited by ross 17 18 and extended by huberman 9 has provided the basis of an extensive literature as for example brown and weinstein 1 chen 3 hughes 10 ingersoll 11 jobson 12 reinganum 15 roll and ross rr 16 and shanken 17 to mention but a few it has also been treated in a more general context by chamberlain and rothschild 2 our purpose here is not to comment on this collection of papers many of which are unpublished but to reexamine the evidence presented by rr and point out major pitfalls involved in the empirical methodology employed by them and others who have followed their lead rr claim that on theoretical and more importantly on empirical grounds arbitrage pricing theory apt is an attractive alternative to the capital asset pricing model capm the apt it is argued requires less stringent and presumably more plausible assumptions is more readily testable since it does not require the measurement of the market portfolio and may be better able to explain the anomalies found in the application of the capm to asset returns the acceptability of the apt like that of the capm or any other theory ultimately depends on its ability to explain the relevant empirical evidence our subsequent discussion will show that many of the prqblems associated with the capm are also present in the apt context and that its ability to explain the relevant empirical evidence is not markedly superior moreover it raises questions not only about the rr and related empirical investigations of the apt but also about the testability of that theory in the present state of the art a major part of the problem results from the necessity to break down the universe being analyzed through the apt model this is forced upon the investigator by the fact

the empirical foundations of the arbitrage pricing theory abstract this paper uses maximum likelihood factor analysis of large cross sections to examine the validity of the arbitrage pricing theory apt we are unable to explain the expected returns on firm size portfolios although we do explain the expected returns on portfolios formed on the basis of dividend yield and own variance where risk adjustment using the usual capm market proxies fails we also compare alternate versions of the apt and sharply reject the hypothesis that basis portfolios formed to mimic the factors span the mean variance frontier of the individual assets

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

does participation in the conservation reserve program impact the economic well being of farm households this study uses u s farm household survey data to examine how participation in the conservation reserve program crp affects farm household economic well being further the study also examines the effects of crp participation on farm household consumption income and imputed savings in contrast to previous studies that assume the relationships are homogenous across the population quantile regression is used to investigate the association between crp participation across the entire distribution of farm household consumption and income empirical findings suggest that the effect of crp participation on household economic well being differs across the income and consumption distribution for households in the lower percentiles of the distribution the crp participation is associated with an increase in household consumption but a decrease in farm household income and savings in contrast farm households at the median and higher income and consumption quantiles participation in crp is associated with lower levels of household consumption and income but with higher levels of savings

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

inflation and taxation nominal and real rates of return abstract the impact on rates of return of an expected change in the rate of inflation is examined in a general equilbrium framework explicit expressions are derived for the marginal relationships between the rate of inflation and nominal and real interest rates one of the conclusions is that with taxation included the nominal rate of interest will tend to increase more than corresponding to the pure fisher effect but less than required to keep consumers after tax real rate of return and the consumption equilibrium unchanged finally some of the implications of the model for the pricing of indexed bonds are examined in a partial equilibrium framework

the effects of farm subsidies on farm exports in the united states we estimate the elasticity of u s farm exports to u s farm subsidies using a gravity model of state level farm exports to 100 major trading destinations for the period 1999 to 2011 our identification strategy exploits the within state variation that is free of endogeneity bias in the levels and trends of farm subsidies and farm exports we find that a 1 decrease in farm subsidies would reduce u s farm exports by 0 40 per annum this equivalently means that the complete abolishment of the farm subsidy program would reduce u s farm exports by approximately 15 3 billion per year importantly we document robust evidence that amber box subsidy programs such as counter cyclical payments and marketing loan gains have the strongest effect on farm exports while green box subsidy payments such as direct payments have negligible effects finally subsidy payments affect exports only in agricultural commodities not in livestock our subsidy elasticity estimates are statistically significant stable and economically meaningful and are vitally needed by u s and global policymakers in the face of critical domestic and international developments

an empirical comparison of alternative models of capital asset pricing in germany abstract in an empirical investigation this research finds that the capm is a better explanatory model of risk return relationships in the german stock market than the ccapm

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

a unified beta pricing theory abstract this paper derives ross s mutual fund separation theory and a new equilibrium version of ross s arbitrage pricing theory as special cases of a general theory the paper also reveals that the two theories are identical in their predictions of asset prices and portfolio returns the capital asset pricing model a restricted case of the mutual fund separation theory receives special treatment

reference variables factor structure and the approximate multibeta representation the arbitrage pricing theory apt implies that if asset returns have a factor structure then an approximate multibeta representation holds with respect to the factors as reference variables this paper assumes that asset returns satisfy a factor structure and derives a condition under which the approximate multibeta representation holds with respect to a set of reference variables which may not be the factors this condition is that the regression matrix of the reference variables on the factors is nonsingular implications for the testability of the apt are also discussed

posterior predictive and utility based approaches to testing the arbitrage pricing theory abstract to provide a framework for judging the economic significance of departures from the arbitrage pricing theory we adopt a utility based metric based on optimal portfolio choices this measure is examined using both predictive and posterior analysis our predictive analysis shows very large and economically significant departures from the model restrictions however the high level of parameter uncertainty suggests that we cannot conclusively either affirm or reject the apt our conclusions differ markedly from other studies which employ traditional significance testing procedures and in many instances fail to reject the apt restrictions

asset trading transaction costs and the equity premium summary a model is developed that attempts to explain the historical size of the us equity premium by distinguishing between gross and net returns accruing to agents the model derived by mehra and prescott 1985 is augmented with a bid ask spread calibrated and simulated equity premia in the order of 3 4 are generated for plausible values of the transactions parameters this contrasts with mehra and prescott who find a maximum equity premium of 0 4 while the historic equity premium has been about 6 2 estimates of the bid ask spread are obtained using gmm and tests of the overidentifying restrictions are not rejected for several lists of instrumental variables

the current state of the arbitrage pricing theory this paper provides a simple proof of a recent theorem presented by reisman 1992 concerning the use of proxies for the factors in the return generating process of the arbitrage pricing theory apt in the single factor case the theorem asserts that any variable correlated with the factor can serve as the benchmark in an approximate apt expected return relation the significance of this result is considered and a new direction for empirical work on arbitrage pricing is outlined given a factor model for an infinite sequence of asset returns ross 1976 showed that the absence of arbitrage implies an approximate linear relation between expected returns and the factor betas ross assumed that returns conform to a strict factor structure i e a factor model with uncorrelated disturbances but noted that this condition could be weakened in deriving the arbitrage pricing theory apt nonetheless statistical methods based on the strict factor model assumption dominated the early empirical work on the apt at first glance the requirement of a strict factor structure appeared to impose a strong restriction on the sets of factors that could be used as a benchmark for measuring systematic risk shanken 1982 demonstrated though that virtually any variables could serve as the factors in a welldefined strict factor model one need only repackage an initial finite set of assets into an equivalent set of portfolios in order to fundamentally alter the associated factor space 2 thus the statistical assumptions underlying the apt cannot by themselves characterize the economically relevant components of returns chamberlain and rothschild 1983 shifted attention away from strict factor structures by proving that the apt holds more generally if returns conform to an approximate factor model 3 in this case the disturbances need

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

food vs fiber an analysis of agricultural support policy in turkey the present study evaluates the effects of agricultural policies on farm land allocation the analysis is applied to turkey a country where a persistent gap between rural income and urban income has motivated governments to enact policies that support farm income this paper evaluates two sets of policy instruments output support which increases farm revenue from specific crops and input support which subsidizes particular farm inputs it also investigates the effects of agricultural policy on farmers incentive to produce fiber cotton versus food corn and other foods using farm level data from two regions of turkey the analysis finds that input supports have had stronger effects on land allocation than output supports it also shows the presence of significant substitution effects across crops with the subsidizing of cotton having a significant negative effect on the incentive to grow food crops this provides useful insights into the economic tradeoff between food and fiber in the design of agricultural policy and its effects on a country s food security

another look at decoupling additional evidence on the production effects of direct payments an important shift in u s agricultural policy occurred with the 1996 federal agriculture improvement and reform fair act although the actual intent and effects of the act remain a topic of debate many observers believed that the 1996 legislation signaled a transition toward a new policy environment characterized by diminished government involvement in agricultural markets perhaps the biggest change in policy under the act pertained to the use of fixed decoupled payments called production flexibility contract or agricultural market transition act amta payments under the terms of the fair act amta payments were intended to decline each year until the fair act expired in 2002 however periods of low prices and localized yield shortfalls during the late 1990s led congress to pass supplemental ad hoc payments to farmers these payments known as market loss assistance were also decoupled since they were paid on the basis of historical base acreage and thus carried no current production requirements these payments were however tied to market prices in that they were a response to poor market conditions

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

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

the impact of decoupled payments on farm choices conceptual and methodological challenges abstract in this paper we review the methodological framework for analysing decoupled payments in models of agricultural production market and technological uncertainty farm efficiency credit constraints farm household choices involving extra agricultural decisions policy uncertainty and long run impact of decoupling on investment and land values are the relevant issues that should be pursued by methodological and empirical analysis future research should refine the analysis of decoupled payments mainly trying to provide results that can be useful for policy simulation to bridge the gap between analysis at the individual level and sector policy models

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

making inefficient market indices efficient this paper uses the concept of marginal conditional stochastic dominance and a generalization of the 50 portfolio rule to develop a tractable and parsimonious methodology for constructing a second degree stochastic dominance ssd efficient portfolio from a given inefficient index because the ssd approach considers the entire probability distributions of asset returns the resulting portfolios are efficient with respect to all risk averse utility maximizing investors regardless of the form of their utility functions or the distributions of asset returns