efficient diversification according to stochastic dominance criteria this paper develops the first operational tests of portfolio efficiency based on the general stochastic dominance sd criteria that account for an infinite set of diversification strategies the main insight is to preserve the cross sectional dependence of asset returns when forming portfolios by reexpressing the sd criteria int dimensional euclidean space with elements representing rates of return int different states of nature we characterize subsets of this state space that dominate a given evaluated return vector by first and second order sd this allows us to derive simple sd efficiency measures and test statistics computable by standard mathematical programming algorithms the sd tests and efficiency measures are illustrated by an empirical application that analyzes industrial diversification of the market portfolio

stochastic dominance and mean variance measures of profit and loss for business planning and investment in this paper we first extend the stochastic dominance sd theory by introducing the first three orders of both ascending sd asd and descending sd dsd to decisions in business planning and investment to risk averse and risk loving decision makers so that they can compare both return and loss we provide investors with more tools for empirical analysis with which they can identify the first order asd and dsd prospects and discern arbitrage opportunities that could increase his her utility as well as wealth and set up a zero dollar portfolio to make huge profit our tools also enable investors and business planners to identify the third order asd and dsd prospects and make better choices to complement the stochastic dominance approach we also introduce an improved mean variance criterion to decisions in business planning or investment on both return and loss for risk averse and riskloving investors we then illustrate the superiority of the present approaches with well known examples in the literature and discuss the relationship between the improved stochastic dominance and mean variance criteria

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

impacts of us biodiesel mandates on world vegetable oil markets abstract in this paper we seek to understand the impact of expanded use of soybean oil biodiesel to address biofuel mandates on global vegetable oil markets and in particular on the demand for palm oil an open economy equilibrium model is derived to investigate the market effects of biodiesel expansion on related energy and vegetable oil markets the model is calibrated to represent the recent benchmark data in calendar year 2014 the simulation estimates suggest that the expanded use of soy oil for biodiesel in the us will have considerable impacts on world vegetable oil markets the majority of the vegetable oil replacement is likely to occur through substitution of palm oil under a wide range of plausible elasticity values on the demand for vegetable oil and the demand substitution between soy oils and palm oils

in the same boat but not equals the heterogeneous effects of parental income on child labour this paper examines the impact of parental income on child labour the empirical literature has found conflicting results regarding whether poverty leads parents to send their children to work mos

almost marginal conditional stochastic dominance marginal conditional stochastic dominance mcsd developed by shalit and yitzhaki 1994 gives the conditions under which all risk averse individuals prefer to increase the share of one risky asset over another in a given portfolio in this paper we extend this concept to provide conditions under which most and not all risk averse investors behave in this way instead of stochastic dominance rules almost stochastic dominance is used to assess the superiority of one asset over another in a given portfolio switching from mcsd to almost mcsd amcsd helps to reconcile common practices in asset allocation and the decision rules supporting stochastic dominance relations a financial application is further provided to demonstrate that using amcsd can indeed improve investment efficiency

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

frontier based vs traditional mutual fund ratings a first backtesting analysis we explore the potential benefits of a series of existing and new non parametric convex and non convex frontier based fund rating models to summarize the information contained in the moments of the mutual fund price series limiting ourselves to the traditional mean variance portfolio setting we test in a simple backtesting setup whether these efficiency measures fare any better than more traditional financial performance measures in selecting promising investment opportunities the evidence points to a remarkable superior performance of these frontier models compared to most but not all traditional financial performance measures

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

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

technology spillovers and land use change empirical evidence from global agriculture we estimate the effects of agricultural technological progress on cropland expansion at various geographical resolutions from the country level to the world as a whole while formally accounting for the international interdependence of national supply responses evidence for these effects has thus far been scant contributing to polarized perceptions about the potential for improving agricultural technologies as a means to slow down deforestation we find that in most countries of the world growth in total factor productivity tfp is either uncorrelated or is positively associated with cropland expansion yet worldwide tfp growth have been an important source of global land savings the divergence between the country level and the global results is explained by the changes in production patterns as countries interact in international markets our preferred point estimate of the elasticity of global cropland to global tfp growth is 0 34 moreover we estimate that satisfying food demand from 1991 to 2010 without observed tfp growth would have necessitated an additional 173 million hectares or close to 10 of the area covered by tropical rain forests

relative undernutrition in puerto rico under alternative food assistance programmes in the early 1980s puerto rico experienced a conversion from the food stamp program fsp to the nutrition assistance program nap and a severe recession to compare relative undernutrition in puerto rico in 1977 and 1984 stochastic dominance methods and statistical inference procedures are applied to nutrient distributions to separate the effect of the recession from the effect of converting food coupons to cash benefits a multiple regression model of nutrient consumption is also estimated in the dominance comparisons every improvement in nutrition status between 1977 and 1984 is statistically significant at the lowest quintile while no case of worsening undernutrition is significant at the lowest quintile the multiple regression model provides some evidence that the conversion from food coupons to cash might have reduced nutrition status in the lowest quintile but a larger proportion of food assistance was allocated to low income households under the nap than under the fsp no evidence of signi

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

sharing the cost of a public good an incentive constrained axiomatic approach we study the problem of provision and cost sharing of a public good in large economies where exclusion complete or partial is possible we search for incentive constrained efficient allocation rules that display fairness properties population monotonicity says that an increase in population should not be detrimental to anyone demand monotonicity states that an increase in the demand for the public good in the sense of a first order stochastic dominance shift in the distribution of preferences should not be detrimental to any agent whose preferences remain unchanged under suitable domain restrictions we give an explicit characterization of all incentive constrained efficient allocation rules we then show that there exists a unique incentive constrained efficient and demand monotonic allocation rule the so called serial rule in the binary public good case the serial rule is also the only incentive constrained efficient and population monotonic rule

oil price biofuels and food supply abstract the price of oil could play a significant role in influencing the expansion of biofuels but this issue has yet to be fully investigated in the literature using a global computable general equilibrium cge model this study analyzes the impact of oil price on biofuel expansion and subsequently on food supply the study shows that a 65 increase in oil price in 2020 from the 2009 level would increase the global biofuel penetration to 5 4 in 2020 from 2 4 in 2009 if oil prices rise 150 from their 2009 levels by 2020 the resulting penetration of biofuels would be 9 which is higher than that would be caused by current mandates and targets introduced in more than forty countries around the world the study also shows that aggregate agricultural output drops due to an oil price increase but the drop is small in major biofuel producing countries as the expansion of biofuels would partially offset the negative impacts of the oil price increase on agricultural outputs an increase in oil price would reduce global food supply through direct impacts as well as through the diversion of food commodities and cropland towards the production of biofuels

land allocation effects of the global ethanol surge predictions from the international fapri model we quantify the emergence of biofuel markets and its impact on world agriculture using the multimarket multicommodity international fapri model the model incorporates trade offs between biofuel feed and food production and consumption and international feedback effects of the emergence through world prices and trade we shock the model with exogenous changes in ethanol demand first in the united states then in brazil and other countries and compute shock multipliers for land allocation decisions for important crops and countries the brazilian ethanol expansion using sugarcane has fewer consequences on existing arable land allocation than the u s ethanol expansion does using corn feedstock

child labor and household land holding theory and empirical evidence from zimbabwe summary the relationship between rural household productive assets and child labor in developing countries is complex some empirical evidence shows that child labor tends to increase as land holding increases or there is an inverted u shaped curve relationship between the probability of putting children to work and land holding this paper shows that the relationship between use of children as laborers and land holding is nuanced child labor generally decreases as per capita land holding increases but there can be an upward bump in the relationship between child labor and landholding near the middle of the range of land per capita the bump can be explained theoretically by the relationship between the marginal productivity of a child worker on the farm and the marginal value placed on his her education at different levels of wealth this pattern is repeated in three surveys conducted in zimbabwe in 2001 2007 8 and 2010 11 from the perspective of policy making the policy maker should be alerted that the programs to promote school retention should not necessarily focus only on the poorest households in rural areas there is a high probability that middle wealth households put their children to work and this probability may change by some other factors such as gender of child and agro ecological conditions

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

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

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

trade in technology a potential solution to the food security challenges of the 21st century abstract the recent rise in caloric undernutrition in sub saharan africa ssa demonstrates the continued relevance of the malthusian footrace between food availability and population sluggish growth in farm productivity in ssa has brought to the fore the key role of agricultural technology in alleviating future food insecurity we develop a model of technology food security and international trade with three distinct channels for technology reduce food insecurity in ssa the first is via greater domestic r d investment an alternative is to import technologies from other countries with significant knowledge capital the third role for technology to resolve the malthusian dilemma in ssa is that of virtual technology trade i e importing technological investments undertaken elsewhere through cheaper imported food to assess the relative contribution of each channel to food security in africa we employ a partial equilibrium quantitative trade model augmented by a temporal relationship between r d investments knowledge capital and agricultural productivity over the historical period 1991 2011 we find that direct r d investments in ssa have been the dominant vehicle for lowering food prices in africa looking forward to 2050 we find that virtual technology trade will be the most important vehicle for reducing non farm undernutrition in africa

acreage decisions under risk the case of corn and soybeans an acreage supply response model is developed under expected utility maximization the resulting framework is used to specify and estimate a system of risk responsive acreage equations for corn and soybeans in the united states particular attention is given to the truncation effects of government price supports on the distribution of corn and soybean prices also a wealth variable is included in the acreage equations the empirical results indicate that risk and wealth variables play an important role in cornsoybean acreage decisions the analysis also shows that cross commodity risk reduction is important in acreage allocation decisions

changes in the u s wage structure 1963 1987 application of quantile regression the 1980 s witnessed rapid changes in the structure of wages in the united states in this study recently developed techniques for quantile regression are applied to every march current population survey since 1964 and changes in the return to schooling and experience at different points of the wage distribution are examined the quantile regression technique parsimoniously describes the entire conditional wage distribution this conditional distribution is used to examine changes in within group wage inequality as measured by the difference between conditional quantiles two linear models are considered a simple one group model and a 16 group model the results suggest that the returns to schooling and experience differ across quantiles of the wage distribution but their patterns of change are similar significant differences in wage inequality are also found across the various skill groups the paper also presents a new imputation method for cps data

consistent testing for stochastic dominance under general sampling schemes we propose a procedure for estimating the critical values of the extended kolmogorov smirnov tests of stochastic dominance of arbitrary order in the general k prospect case we allow for the observations to be serially dependent and for the first time we can accommodate general dependence amongst the prospects which are to be ranked also the prospects may be the residuals from certain conditional models opening the way for conditional ranking we also propose a test of prospect stochastic dominance our method is based on subsampling and we show that the resulting tests are consistent and powerful against some n 1 2 local alternatives we also propose some heuristic methods for selecting subsample size and demonstrate in simulations that they perform reasonably we describe an alternative method for obtaining critical values based on recentring the test statistic and using full sample bootstrap methods we compare the two methods in theory and in practice

geography matters international trade patterns and the indirect land use effects of biofuels this article investigates the relationship between international trade patterns and the global distribution of coarse grain production responses to market developments in the united states our null hypothesis is that world markets are fully integrated rendering the geographic persistence of bilateral trade flows irrelevant in the global production response to a change in us prices the alternative hypothesis allows price transmission to vary along with the intensity of competition among countries in specific markets using data from 1975 to 2002 we reject the null hypothesis our work has direct implications for the analysis of the global land use impacts of biofuel mandates

ranking income distributions a large variety of policy questions involve choices between social states and a consequent ordering of the feasible alternatives when these social states are related to the levels of welfare experienced by individuals or households two central issues stand out in determining the relative desirability of different social outcomes one of these is the essentially positive exercise of achieving comparability between households with different characteristics such as composition or preferences operating in different environments for example facing different price structures the other concerns the normative judgments implicit in the evaluation of alternative allocations of resourcesthe emphasis placed on inequality between households and the extent to which greater inequality can be compensated by higher average living standards this paper focuses on the second of these issues and in doing so we abstract from the problem of household comparability by considering a population of n households identical in all respects except for their incomes the question of ordering social states then becomes one of ranking income distributions over a group of anonymous households or individuals borrowing the usual assumptions imposed on consumer preferences we may suppose that a social ordering of income distributions can be represented by a welfare function 2

a critique of latent variable tests of asset pricing models abstract latent variable tests of asset pricing models make assumptions about the joint distribution of observable returns and unobservable benchmark returns these tests can falsely accept models when a mean variance efficient portfolio other than the benchmark satisfies the distributional assumptions imposed on the benchmark portfolio also because the assumptions are untestable there is no way to discover whether a model is being rejected because the assumptions are false without these assumptions however latent variable tests can be viewed only as tests of distributional hypotheses about mean variance efficient portfolios of unknown composition

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

empirical tests for stochastic dominance efficiency we derive empirical tests for the stochastic dominance efficiency of a given portfolio with respect to all possible portfolios constructed from a set of assets the tests can be computed using straightforward linear programming bootstrapping techniques and asymptotic distribution theory can approximate the sampling properties of the test results and allow for statistical inference our results could provide a stimulus to the further proliferation of stochastic dominance for the problem of portfolio selection and evaluation using our tests the fama and french market portfolio is significantly inefficient relative to benchmark portfolios formed on market capitalization and book to market equity ratio

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

a new approach to international arbitrage pricing this paper uses a nonlinear arbitrage pricing model a conditional linear model and an unconditional linear model to price international equities bonds and forward currency contracts unlike linear models the nonlinear arbitrage pricing model requires no restrictions on the payoff space allowing it to price payoffs of options forward contracts and other derivative securities only the nonlinear arbitragepricing model does an adequate job of explaining the time series behavior of a cross section of international returns the idea that a few relevant state variables explain expected returns is the main driving force of the seminal papers of merton 1973 and ross 1976 these seminal ideas have been extended to the pricing of international assets by ikeda 1991 ross and walsh 1983 solnik 1974 1983 and stulz 1981 among others the key implication of these arbitrage pricing models is that only risks related to these factors state variables are relevant in determining asset prices testable implications of these international asset pricing models have been derived either by placing restrictions on the payoff structure i e payoffs are linear in factors as in ikeda 1991 ross and walsh 1983 and solnik 1983 or on the joint distributions of the payoffs and state variables as in constantinides 1989 these restrictions lead to the testable implication that expected asset returns are linear in the conditional covariances with the factor payoffs in what follows we refer to these models as linear arbitrage models or linear models

statistical inference for the measurement of the incidence of taxes and transfers we establish the asymptotic sampling distribution of general functions of quantile based estimators computed from samples that are not necessarily independent the results provide the statistical framework within which to assess the progressivity of taxes and benefits their horizontal inequity and the change in the inequality of income which they cause by the same token these findings characterise the sampling distribution of a number of popular indices of progressivity horizontal inequity and redistribution they can also be used to assess welfare and inequality changes using panel data and to assess poverty when it depends on estimated population quantiles we illustrate these results using micro data on the incidence of taxes and benefits in canada

calculation and decomposition of income inequality in low and middle income countries a survey data analysis this article estimates income inequality in a sample of four low and middle income lmi countries namely albania nepal tajikistan and tanzania using the household survey data nepal living st

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

child labor and the wealth paradox the role of altruistic parents abstract using data from pakistan we study the effect of family wealth on the utilization of child labor we find evidence of a positive relationship between land wealth and child labor only for children in the upper quantiles of the distribution we hypothesize that the so called wealth paradox in child labor is driven by parental preferences

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

bootstrap based bias correction for dynamic panels abstract the within or least squares dummy variable estimator is inconsistent for homogeneous dynamic panel models with fixed time dimension t we present a bias correction for this estimator based on an iterative bootstrap procedure monte carlo simulations show that for panels with small to moderate t this procedure provides a good alternative for existing dynamic panel data estimators

theories of risk testing investor behaviour on the taiwan stock and stock index futures markets investor behavior towards risk lies at the heart of economic decision making in general and modern investment theory and practice in particular this paper uses both the mean variance mv criterion and stochastic dominance sd procedures to analyze the preferences for four of the most widely studied investor types in the taiwan stock and stock index futures market we find that risk averters concave utility function prefer spot to futures whereas risk seekers convex utility function prefer futures to spot our findings also show that investors with s shaped utility functions prefer spot futures to futures spot when markets move upward downward finally our results imply that investors with reverse s shaped utility functions prefer futures spot to spot futures when markets move upward downward these results are robust with respect to sub periods spot returns including dividends and diversification although we do not check whether risk averters risk seekers and investors with s shaped and reverse sshaped utility functions actually exist in the market we do show that their existence is plausible the implications of our findings on market efficiency and the existence of arbitrage opportunities are also discussed in this study

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

an exogeneity test for a simultaneous equation tobit model with an application to labor supply a test of weak exogeneity in the simultaneous equation tobit model is proposed and illustrated using a female labour supply model estimated using cross section data the test statistic can be simply output from any standard tobit maximum likelihood package and is asymptotically efficient the procedure provides consistent estimators for the simultaneous tobit model whose asymptotic covariance matrix is a simple extension of the usual tobit formula we also provide the lagrange multiplier test of weak exogeneity this abstract was borrowed from another version of this item

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

specific experience household structure and intergenerational transfers farm family land and labor arrangements in developing countries data from indian rural household survey was used to test th hypothesis that the coexistence in traditional rural societies of extended intergenerational families infrequent land sales and high reliance on family members as farm laborers is the result of the economic advantages which accrue from the knowledge gained by farming a particular ploy of land over a long period of time the land specific experience of elderly members of a intergenerational household who farmed the land as a child and then as an adult are expecially critical in adverse weather years most previous investigators attributed the existence of multigenerational households the use of family members rather than hired laboreds and the infrequency of land sales to deficiencies in the market i e labor market imperfections and an absence of capital insurance and asset markets in the present investigations these same characteristics are viewed as having an economic advantages a model for estimating the contribution of the experience of the elderly household members to agricultural profits was developed and applied to data from a 3 year panel study of 2900 indian rural farm households the data was collected between 1968 71 by the national council of applied economic research the survey collected information on farm profits farm inputs demographic characteristics and the effects of weather conditions on profits a major limitation of the study was a lack of information on the duration of land ownership age of household members was substituted as a proxy for duration of ownership findings were consistent withe the hypothesis in poor agricultural years gross returns for households which contained an elderly household member were greater than the gross returns for comparable households which did not contain an elderly member the economic advantages of specific knowledge embodied in the experienced elderly farmer were comparable to the economic advantages which accrued to households whose members were more educated the hypothesis cannot fully explain the existence of intergenerational families since there is a relatively large proportion of such families among nonfarm families in many countries including india findings suggest that intergenerational families may provide for more occupational diversity and thereby reduce income risks the specific experience hypothesis has policy implications if technological changes are introduced the value of specific experience may be lost and the frequency of intergenerational households may decline the hypothesis may also explain why farmers are reluctant to agree to land redistribution and consolidation schemes this reluctance may disappear after sufficient technological change has occurred

international comparisons of welfare and poverty dominance orderings for ten countries inference based stochastic dominance procedures are applied to luxembourg income study data to rank ten western countries in terms of standards of living and poverty first order dominance comparisons ranks more than 50 percent of all pairwise comparisons and second order generalized lorenz dominance adds another 25 percent truncated dominance analysis is used to make inferences about poverty and up to 98 percent of the truncated distributions are ordered the results differ substantially from those obtained when only relative incomes and inequality are considered

the impossibility of a progressive tax structure abstract when households are identical in all respects other than income a non decreasing average tax rate is both necessary and sufficient for post tax incomes to be always at least as equal as pre tax incomes this paper investigates whether this well known result can be extended to households with different needs a tax structure which never increases inequality in the lorenz sense is shown to be unable to discriminate between household types if in addition the tax structure never reduces the relative income of the poorest member of the neediest group of households then the same proportional tax must be applied to all households and redistribution is impossible either within or between groups of households with differing needs a similar conclusion is reached using conventional equivalence scale arguments and also applies when the parameters of the tax schedules are determined endogenously we discuss the significance of this impossibility result and its implications for tax design

what mean impacts miss distributional effects of welfare reform experiments labor supply theory predicts systematic heterogeneity in the impact of recent welfare reforms on earnings transfers and income yet most welfare reform research focuses on mean impacts we investigate the importance of heterogeneity using random assignment data from connecticut s jobs first waiver which features key elements of post 1996 welfare programs estimated quantile treatment effects exhibit the substantial heterogeneity predicted by labor supply theory thus mean impacts miss a great deal looking separately at samples of dropouts and other women does not improve the performance of mean impacts we conclude that welfare reform s effects are likely both more varied and more extensive than has been recognized

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

the economics of child labor if child labor as a mass phenomenon occurs not because of parental selfishness but because of the parents concern for the household s survival the popular argument for banning child labor loses much of its force however this assumption about parental decision making coupled with the assumption of substitutability in production between child and adult labor could result in multiple equilibria in the labor market with one equilibrium where children work and another where adult wage is high and children do not work the paper establishes this result and discusses its policy implications copyright 1998 by american economic association

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

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

the indirect land use impacts of united states biofuel policies the importance of acreage yield and bilateral trade responses recent work has highlighted agricultural land conversion as a significant debit in the greenhouse gas accounting of ethanol as an alternative fuel this work has at the same time sparked considerable debate on the role of crop yield growth as a means of avoiding rapid land conversion we examine the agricultural land use impacts of mandate driven ethanol demand increases in the united states in a formal economic equilibrium framework which allows us to examine the importance of yield price relationships we find that the standard assumption of trend yield growth is likely restrictive for analysis of equilibrium response to significant demand increases for fuel feedstocks furthermore we identify both the acreage response and bilateral trade specification of a multi country model as important sources of variability in terms of parametric uncertainty in predicting global land use change from the biofuels boom

a note on asset proportions stochastic dominance and the 50 rule in this note we analyze the composition of an optimal portfolio by considering the cumulative conditional expected outcome of two dependent assets we develop a conditional stochastic dominance relation and show that for any concave von neumann morgenstern utility function the proportion of wealth invested in the dominant asset will be greater than 50

portfolio choice based on third degree stochastic dominance we develop an optimization method for constructing investment portfolios that dominate a given benchmark portfolio in terms of third degree stochastic dominance our approach relies on the properties of the semivariance function a refinement of an existing superconvex dominance condition and quadratic constrained programming we apply our method to historical stock market data using an industry momentum strategy our enhanced portfolio generates important performance improvements compared with alternatives based on mean variance dominance and second degree stochastic dominance relative to the center for research in security prices all share index our portfolio increases average out of sample return by almost seven percentage points per annum without incurring more downside risk using quarterly rebalancing and without short selling this paper was accepted by lauren cohen finance

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

bonds versus stocks investors age and risk taking abstract it has become increasingly popular to advise investors to relocate their funds from a primarily stock portfolio to a primarily bond portfolio as they get older however the well known decision rules such as mean variance or stochastic dominance rules are unable to explain this common practice almost stochastic dominance asd and almost mean variance amv approaches are used to examine the dominance of stock and bond portfolios asd and amv rules unambiguously support the popular practice of advising higher stock to bond ratio for long investment horizons hence we provide an explanation to the practitioners recommendation within the expected utility paradigm

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

marginal conditional stochastic dominance this paper introduces the concept of marginal conditional stochastic dominance mcsd which states the conditions under which all risk averse individuals when presented with a given portfolio prefer to increase the share of one risky asset over that of another mcsd rules also answer the question of whether all risk averse individuals include a new asset in their portfolio when assets returns are correlated mcsd criteria are expressed in terms of the probability distributions of the assets and of the underlying portfolio an empirical application of mcsd is provided using stocks traded on the new york stock exchange mcsd rules are used to show that in the long run one cannot assert that the market portfolio is inefficient

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

on the transmission of world agricultural prices two questions are asked about the relationship between domestic prices and world prices of agricultural commodities are variations in world prices transmitted to domestic prices domestic prices are regressed on world prices in various forms taking into account the possible effects of exchange rates and inflation the empirical analysis is based on data from the food and agriculture organization of the united nations for 58 countries from 1968 78 and for the countries of the european community from 1961 85 the results show that most of the variations in world prices are transmitted and that they constitute the dominant component in the variations of domestic prices

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

competition for land in the global bioeconomy the global land use implications of biofuel expansion have received considerable attention in the literature over the past decade model based estimates of the emissions from cropland expansion have been used to assess the environmental impacts of biofuel policies and integrated assessment models have estimated the potential for biofuels to contribute to greenhouse gas ghg abatement over the coming century all of these studies feature explicitly or implicitly competition between biofuel feed stocks and other land uses however the economic mechanisms governing this competition as well as the contribution of biofuels to global land use change have not received the close scrutiny that they deserve the purpose of this article is to offer a deeper look at these factors we begin with a comparative static analysis which assesses the impact of exogenously specified forecasts of biofuel expansion over the period 2006 2035 global land use change is decomposed according to the three key margins of economic response extensive supply intensive supply and demand under the international energy agency s new policies scenario biofuels account for nearly one fifth of global land use change over the 2006 2035 period the article also offers a comparative dynamic analysis which determines the optimal path for first and second generation biofuels over the course of the entire 21st century in the absence of ghg regulation the welfare maximizing path for global land use in the face of 3 annual growth in oil prices allocates 225 mha to biofuel feed stocks by 2100 with the associated biofuels accounting for about 30 of global liquid fuel consumption this area expansion is somewhat diminished by expected climate change impacts on agriculture while it is significantly increased by an aggressive ghg emissions target and by advances in conversion efficiency of second generation biofuels jel classifications q11 q15 q24 q42 q54

pricing and risk management of interest rate swaps this paper reformulates the valuation of interest rate swaps swap leg payments and swap risk measures all under stochastic interest rates as a problem of solving a system of linear equations with random perturbations a sequence of uniform approximations which solves this system is developed and allows for fast and accurate computation the proposed method provides a computationally efficient alternative to monte carlo based valuations and risk measurement of swaps this is demonstrated by conducting numerical experiments and so our method provides a potentially important real time application for analysis and calculation in markets

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

allocatable fixed inputs and jointness in agricultural production implications for economic modeling allocatable fixed inputs such as land are a potentially important source of jointness in agriculture as with other causes of jointness they necessitate multiple product systems for modeling product supply and input demand in other important ways however their analytical implications are very different from other causes of jointness model specification differs demand functions for the quantities of each input used in the production of individual commodities can be derived if a primal approach is used but such allocation equations cannot in general be identified from a dual specification available allocation data are not even useful in such dual estimations

towards more accurate and policy relevant footprint analyses tracing fine scale socio environmental impacts of production to consumption the consumption of internationally traded goods causes multiple socio environmental impacts current methods linking production impacts to final consumption typically trace the origin of products back to the country level lacking fine scale spatial resolution this hampers accurate calculation of trade and consumption footprints masking and distorting the causal links between consumers choices and their environmental impacts especially in countries with large spatial variability in socio environmental conditions and production impacts here we present the sei pcs model spatially explicit information on production to consumption systems which allows for fine scale sub national assessments of the origin of and socio environmental impacts embedded in traded commodities the method connects detailed production data at sub national scales e g municipalities or provinces information on domestic flows of goods and in international trade the model permits the downscaling of country to country trade analyses based on either physical allocation from bilateral trade matrices or mrio models the importance of producing more spatially explicit trade analyses is illustrated by identifying the municipalities of brazil from which different countries source the brazilian soy they consume applications for improving consumption accounting and policy assessment are discussed including quantification of externalities of consumption consumer labeling trade leakages sustainable resource supply and traceability

testing the significance of income distribution changes over the 1980s business cycle a cross national comparison using kernel density estimation we describe the distribution of household size adjusted real income and how it changed over the business cycle of the 1980s in the united states and the united kingdom we confirm previous studies that show income inequality increased in the two countries and the middle of the distribution was squashed down using a series of statistical tests however we find that while the mass in both tails of the distribution increased significantly in both countries over the period by far the greatest gains were in the upper tail copyright 1999 john wiley sons ltd

dollars and dreams a reduced middle class alternative explanations we decompose annual earnings into hours of work and hourly earnings and analyze male female differences in earnings inequality using canadian data our results indicate that the larger female inequality in earnings is due to a greater inequality in the

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

economic growth a panacea for child labor summary in this paper we test whether economic growth decreases child labor by bringing together data from the national sample survey of india and state level macrodata to estimate a bivariate probit model of schooling and labor our results lead us to conclude that contrary to popular wisdom growth actually increases rather than decreases child labor because it increases the demand for child workers the level of state ndp village wages and household incomes are seen as the conduits through which growth influences the supply side of the child labor market

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

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

income distribution in the dynamic two factor trade model the issue of the effects of trade on personal income distribution has remained largely unexamined this paper describes an overlapping generations 2 x 2 model with a bequest motive and heterogeneous agents in order to examine the problem in this dynamic setting trade leads to both short run and long run reductions increases in inequality in labor capital abundant countries if the investment good is capital intensive if the consumption good is capital intensive the short run effects continue to hold but the long run effects are ambiguous copyright 1992 by the london school of economics and political science

asset proportions in optimal portfolios the paper is concerned with conditions under which the proportion of a given asset in the optimal portfolio of a risk averse agent is at least as large as some given proportion the paper provides a condition that is necessary and sufficient for such a result to hold the analysis is then confined to portfolios in which the distributions of assets differ by either a first degree stochastic dominance shift or by a mean preserving shift examples are provided to show that under some conditions a risk averter may invest a smaller proportion of his wealth in the dominating asset than in the dominated asset the paper then provides conditions that are necessary and sufficient for a risk averter to invest more in the dominating asset the question of whether risk averse agents should or should not choose diversified portfolios as opposed to specialized ones has been analysed quite extensively in the literature examples of such works are samuelson 1967 brumelle 1974 hadar and russell 1974 russell and seo 1979 hadar and seo 1980 and macminn 1984 what has not been examined at all except for very special cases is the question of the optimal proportions of the various assets in a diversified portfolio in this paper we present conditions which imply that the optimal amount invested in a particular asset is at least as large as some given proportion of the available fund in the case of two asset portfolios one may especially want to know which of the two assets represents more than half the investible fund indeed we find it convenient to start the analysis with the two asset case while the extension to n asset protfolios is essentially straightfoward it is presented in a subsequent section focusing first on the two asset case will make it easier for the reader to see the main logical steps in the proofs of the theorems some of our analysis is facilitated by the use of a particular subset of risk averters this subset has the property that if its members behave in a particular way then all risk averters behave in that way we refer to such a subset as a representative set of all risk averters 2 the usefulness of the representative set derives from the fact that its members have utility functions of a very simple form consisting of two linear pieces and its applicability to the problems on hand derives from the fact that any concave function can be approximated by a linear combination of members of the representative set in the next section we present some formal results demonstrating the equivalence of unanimity among members of the representative set and unanimity among all risk averters in certain types of choice situations these theorems are then used in section 3 in which we present the results about optimal asset proportions