integration of var and expected utility under departures from normality this article identifies the level of the expected utility eu risk aversion and value at risk var confidence level that yield the same choice from a given distribution of outcomes and thus allow for consistent application of the two criteria the result for a given distribution is an explicit mapping between risk aversion under eu and var for both normal and nonnormal distributions the cornish fisher expansion is used to establish adjusted mean deviates for nonnormal outcome distributions and the investor s preference function is expanded to include elements for variance skewness and excess kurtosis a farm level application with nonnormal revenue distribution illustrates these approaches

unionization and input flexibility in u s manufacturing 1973 1996 input flexibility as measured by the ability of firms to vary input demand in the face of changes in input prices is an important dimension of labor market flexibility using a new dataset the authors analyze the impact of unionization on input flexibility in u s manufacturing from 1973 to 1996 a period in which production was arguably becoming more flexible due to deep changes in the u s industrial relations system and in the broad macroeconomic environment the authors quantify the effects of unionization on input flexibility by estimating elasticities of substitution between a broad range of labor and non labor inputs controlling for unionization the pattern that emerges is more complex than that suggested by other research in particular low unionization apparently is associated with greater flexibility in the use of labor inputs but less flexibility in the use of non labor inputs

a general mean variance approximation to expected utility for short holding periods the mean variance model is precisely consistent with the expected utility hypothesis only in the special cases of normally distributed security returns or quadratic utility functions there is little evidence however that security returns follow normal distributions see 13 for references and quadratic preferences can be shown to generate implausible results exhibiting increasing absolute risk aversion in the pratt ll arrow 1 2 sense and displaying negative marginal utility after some finite wealth level in addition hakansson 4 has shown that single period mean variance efficient portfolios can have disastrous consequences over time even when return distributions are stationary such criticisms of the mean variance approach within the von neumann morgenstern framework have prompted several writers to suggest that investors maximize the expected value of utility functions with more realistic properties while others have criticized the single period focus of the model one popular alternative utility function is the logarithmic function which exhibits decreasing absolute risk aversion and conveniently leads to myopic decision processes through time i e investors treat each period as if it were the last basing investment decisions on that period s wealth and return distributions only 8 4 other utility functions with constant relative risk aversion such as the power function also imply myopic decision rules within a multiperiod setting

expected utility chebichev bounds mean variance analysis this paper deals with and answers the following question what are the best upper and lower bounds on expected utility when we know the mean and variance of the random variable involved some applications are also indicated

a note on unionization and the elasticity of substitution if unions force employers off their demand curves the measured elasticity of substitutio n should be lower where unionization is stronger estimates based on pooled data for twenty two digit sic canadian manufacturing industrie s over the period 1971 81 support this proposition point estimates a re that the elasticity is 1 98 in the absence of unions 1 04 if empl oyees are fifty percent unionized and only 0 10 if employees are one hundred percent unionized however the results are not very robust to specification changes

why do farmers have so little interest in futures markets a farm financial model with leverage and investment in two farm enterprises is specified the model is extended to incorporate futures hedging and the separation theorem is used to show that optimal hedging is zero the assumption of a risk free asset is relaxed and while this leads to a violation of the separation theorem the result that optimal hedging is zero is maintained providing that futures markets are efficient it is concluded that if capital markets are efficient then farmers will have little interest in futures markets except to speculate

cellular telephones in the israeli market the demand the choice of provider and potential revenues this study presents the methodology the estimates and a scenario for forecasting the demand for cellular telephones and their use in israel the analysis was based on the integration of three sub models the estimate of the consumer s decision on whether to purchase a cellular telephone and what type was obtained by using a discrete choice model of the multinomial logit type the total number of cellular telephone purchases to be made in israel during the years 1998 2008 was estimated using a logistic growth model employing aggregate data over time the anticipated demand for airtime was based on findings of a survey carried out on a national sample and on actual usage data on the various consumers during the years prior to the survey the research shows the substantial economic potential of israel s cellular telephone market

union nonunion compensation differentials and industry structure abstract this paper examines the impacts of industry output and labor input market structures on workers total compensation in u s manufacturing for empirical analysis cps may 1983 data were matched with 1982 census of manufacturing results indicate that employees in highly concentrated product markets proxied by four firm concentration ratio crr earn more independent of their union membership second union members in the smaller plant sizes have the most to gain and the union advantage disappears for medium to large plants third and perhaps most important the joint effects of unionism and crr on earnings depend on the size of the manufacturing plant in conclusion the paper finds support for dowrick s 1989 conjecture that profits enhancing product market conditions generally tend to increase earnings

on the accuracy of the mean variance approximation for futures markets abstract simple approximate fomulae for the volume and gains from futures trading are derived using the mean variance model the errors involved are exactly quantified and shown to be negligible for the futures price and welfare gains though potentially larger for volumes

input demand elasticities for heterogeneous labor firm level estimates and an investigation into the effects of aggregation labor economists have paid increasing attention to the estimation of demand elasticities for heterogeneous labor the majority of these studies investigate the effect on wage rates resulting from exogenous changes in factor quantities i e the measurement of elasticities of complementarity examples of these studies abound borjas for example investigates the impact of differences in labor market representation on the earnings of racial groups 8 in another paper borjas defines immigrants as a separate labor group and is able to determine the impact of immigration on the wages earned by natives 9 berger defines labor inputs along education and gender lines thereby allowing for the investigation of changes in the age education composition of the work force on wage rates 5 and grant and hamermesh study the effect of increasing female labor force participation on the wages earned by youth and adults 17 less attention has been paid to the study of the responsiveness of employment to exogenous changes in wage rates i e the measurement of elasticities of substitution less attention has been focused on this issue because the data requirements are more stringent since in order to presume that wage rates are exogenously determined the unit of observation must be small ideally establishmentor firm level data would be used the relative inaccessibility of these type of data has led researchers to use more aggregated figures such as smsa level or industry level data to address microissues as long as wage rates are determined exogenously the unit of observation chosen is appropriate there are real concerns however about the adequacy of more aggregated units to describe the behavior of firms 2 this study addresses the issue of whether micro level data are in fact needed to accurately measure elasticities of substitution among labor groups a firm level data set that includes input

estimating demand for local telephone service with asymmetric information and optional calling plans in this paper i study the theoretical and econometric implications of agents uncertainty concerning their future consumption when a monopolist offers them either a unique mandatory nonlinear tariff or a choice in advance from a menu of optional two part tariffs agents uncertainty is resolved through individual and privately known shocks to their types in such a situation the principal may screen agents according to their ex ante or ex post type by offering either a menu of optional tariffs or a standard nonlinear schedule the theoretical implications of the model are used to evaluate a tariff experiment run by south central bell in two cities in kentucky in 1986 the empirical approach explicitly accounts for the existence of informational asymmetries between local telephone users and the monopolist leading to different nested econometric specifications under symmetric and asymmetric information the empirical evidence suggests that there exists a significant asymmetry of information between consumers and the monopolist under both tariff regimes all expected welfare components failed to increase with the introduction of optional tariffs for the estimated value of the parameters copyright 2002 wiley blackwell

the translog approximate function substitution among inputs in manufacturing evaluated at sample means abstract this paper shows the translog function can approximate any first degree homogeneous function around any expansion point estimates for 1987 manufacturing confirm no weak separability of labor from capital but do not confirm lower production than non production worker substitution with capital

optimal market pools for agricultural cooperatives most agricultural marketing cooperatives distribute members net revenues on a pool basis the present paper outlines various pool options and provides a framework for identifying privately and collectively optimal pooling rules individual members pool choices are found to vary according to farm enterprise and risk aversion level a collectively optimal rule depends generally on risk aversion and on the method used to aggregate individuals expressed preferences in the instance examined here however the collective optimum is somewhat insensitive to assumed risk aversion

the rationale of the mean standard deviation analysis skewness preference and the demand for money publisher summary this chapter discusses the rationale of the mean standard deviation analysis skewness preference and the demand for money in january 1969 issue of the review of economic studies karl borch and martin feldstein separately criticized the widely used mean variance analysis of portfolio selection borch contended that any system of upward sloping mean standard deviation e s indifference curves can be shown to be inconsistent with the basic axiom of choice under uncertainty he pointed out that one can always pick any two points on an upward sloping indifference curve to represent two bernoulli distributions with probability 1 p of gaining the same amount x in both the cases and probability p of gaining y1 in the case of one distribution and y2 in the case of the second distribution with y2 y1 if the second distribution represents the point to the northeast of the other point then by the dominance axiom the second distribution must be preferred to the first which contradicts the basic meaning of indifference curves feldstein by using a log utility function and a lognormal distribution for investment outcome showed that e s indifference curves for a risk averter need not be convex downwards though upward sloping they would change from convex to concave once the standard deviation of the outcome exceeds the mean multiplied by on the face of it this seems to suggest that risk aversion might decrease as risk is increased beyond a certain extent

a new foundation for the mean variance analysis abstract in this paper i re examine how the mean variance analysis is consistent with its traditional theoretical foundations namely stochastic dominance and the expected utility theory then i propose a simplified version of the coarse utility theory as a new foundation i prove that by assuming risk aversion and the normality of asset variables the simplified model is well behaved indifference curves are convex and the opportunity set is concave therefore there exist global optimal portfolios in the market finally i prove that decision making in accordance with the simplified model is consistent with the mean variance analysis

neoclassical consumer demand theory and the demand for money m friedman 1956 suggests that the demand for money should be analyzed in terms of consumer demand theory although often the interpretation of empirical results from studies using aggregate data appears to be in terms of the motives approach i e transactions precautionary and speculative motives the authors develop friedman s ideas within an explicit model of consumer theory and find that they provide a consistent framework for analyzing portfolio choice and offer greater insights into results from aggregate studies of the demand for money than the motives approach in particular the authors provide a new interpretation of the role of nominal interest rates inflation and a hicksian measure of wealth in the demand for money function copyright 1991 by royal economic society

targeted and untargeted subsidy schemes evidence from postdivestiture efforts to promote universal telephone service abstract normative economic analysis traditionally has pointed toward the merits of policies wherein prices reflect the economic cost of providing a good or service subsidization policies are nevertheless common in a variety of industries where such subsidies occur economists have long advocated targeting those subsidy flows to maximize their effectiveness and minimizing the allocative inefficiency caused by financing of the subsidy despite the apparent consensus in economic thought on this subject empirical evidence of the relative effectiveness of targeted versus untargeted subsidies to date has been lacking in this article we address this lacuna by examining a set of large scale targeted and untargeted subsidy flows that have developed side by side each with the same nominal policy goal promoting universal telephone service specifically we test empirically the relative contributions of the alternative subsidy mechanisms in promoting the policy goal of maximizing subscription to the public s

theory of the firm with joint price and output risk and a forward market expected utility maximizing farmers facing just price risk or both price risk and quantity risk behave similarly in the absence of a forward market if forward contracting is possible that is not true because variation in the commodity price affects a farmer s wealth through the value of his futures position the value of his output and through the covariance between price and output this covariance affects a farmer s optimal scale of production his optimal forward position and the interrelationship between the scale of production and forward trading

does mean variance portfoliomanagement deserve expected utility s approximative affirmation abstract this article is a comment on the paper by harry markowitz on mean variance approximations to expected utility european journal of operational research 234 2014 436 355 this comment is followed by the reply of harry markowitz

optimal grain pricing and storage policy in controlled agricultural economies application to zimbabwe abstract maize pricing and storage policies of zimbabwe s grain marketing board are compared to those that would be optimal under certain objective function risk and risk aversion assumptions optimal producer prices and storage levels are found to be interdependent and to respond to prices at other levels of the marketing chain the ideal maize reserve stock increases with uncertainty over import transportation costs a factor to consider in light of the threat of south african sanctions but at a reasonable risk aversion level optimal reserves still are much lower than those presently held by the board

simplified risk analysis in agricultural extension abstract attention is given to the major methods of assessing risk in order to make choices the literature frequently reports studies on mean variance e v analysis and stochastic dominance rules both of these methods are compared in an agricultural application with the approach outlined by hanoch and levy the empirical results suggests that hanoch and levy s criterion appear to reduce the size of the risk efficient set and that the sets of recommendations from the methods under comparison were consistent the two recommendations generated by hanoch and levy s rule were found to be reasonable for this particular decision process

risk efficient irrigation strategies for wheat abstract agricultural production is risky when farmers are risk averse they are likely to put a premium on production methods that reduce perceived risks irrigation is generally believed to be a risk reducing input by using the concept of stochastic dominance risk efficient irrigation policies for wheat grown in central india are identified and quantitative estimates of benefits due to risk reduction are obtained such benefits were found to be of a large order of magnitude the more common methods such as mean variance analysis tended to over estimate the benefits

skewness preference risk aversion and the precedence relations on stochastic changes this paper provides a general choice theoretic characterization of the trade off between risk and skewness whose importance in understanding risk taking behavior is well documented in empirical studies the condition under which the prudence measure kimball 1990 characterizes the strength of an individual s downside risk aversion against his own risk aversion is identified and interpreted in a unifying framework based on the concept of one stochastic dominant change preceding another and that of the desirability of a stochastic change the framework is also shown to be useful for a better understanding of the arrow pratt measure the stronger ross measure and the coincidence of the characterizations of downside risk aversion and prudence as well as the relationship between stochastic dominances of different degrees

approximation methods for ranking risky investment alternatives abstract the paper develops and illustrates the application of criteria for ranking risky investment alternatives that are based on their certainly equivalent ce outcomes and determines expressions for approximating the ce outcomes by means of the central moments of their distribution the paper develops criteria on the basis of the ce outcomes for determining a complete ranking of risky investment alternatives that can represent the choice of many though not all risk averse agents

on the proportionality and homogeneity of consumption and income in its certainty equivalence form consumption is proportional to the sum of human and non human wealth with labour income uncertainty the proportionality takes the form of homogeneity of consumption with respect to the components of wealth in this paper we analyse the stochastic properties of labour income that yield the homogeneity property

determination of the recommended hedging ratio the traditional literature on commodity futures markets defined a hedge as a futures market position which is equal but opposite to the individual s cash market position more recent studies have recognized that the futures market position need not equal the cash market position to constitute a hedge many researchers have theoretically solved for the optimal futures and cash market positions for example heifner johnson ward and fletcher and telser determined the optimal futures and cash market positions simultaneously peck determined the optimal futures market position assuming that the cash market position was given the formulas for the optimal futures and cash holdings differ from study to study because of the different underlying assumptions however general implications can be deduced from these studies concerning the size of the optimal hedging ratio i e the ratio of the optimal futures position to the optimal cash position in this paper it is argued that the optimal hedging ratios consistent with the results obtained by johnson ward and fletcher and telser are identical to the optimal hedging ratio derived byheifner 1972 1973 the exercise provides a major implication for hedging strategy which is consistent with all of these studies that the optimal hedging ratio is independent of the individual s risk aversion even though the optimal positions are themselves not independent of the risk parameter this implication is also valid for the minimum risk hedging ratio derived by johnson ederington and mckinnon finally the optimal hedging ratio in peck remains dependent on the risk parameter because the cash market position is assumed to be given

policy reform and labour demand in branches of sri lankan manufacturing industry many policy reforms in developing countries aim to remove factor market distortions whether such reforms reduce unemployment depends partly on the substitution possibilities between labour and other factors of production this paper examines labour demand in seven branches of sri lankan manufacturing industry using data on 4 digit industrial categories over the 1990 to 1997 period the box cox transformation is used to allow for flexible and data dependent elasticities the elasticity of capital labour substitution varies widely across the branches of industry and is usually variable rather than constant the average long run own wage elasticity of labour demand for the manufacturing sector is estimated as 0 80 so factor price policy should have an important effect on labour demand in this setting

the union impact on profits evidence from industry price cost margin data this paper uses industry price cost margin data to estimate the extent to which unions reduce profits estimates allowing for the endogeneity of union status are contrasted with estimates that assume union status is exogenous and not determined in part by either profitability or industry structure endogeneity is found to be an important consideration in estimating the union impact on profits two stage estimates are considerably larger than ols estimates the final section explores the total estimated redistribution from capital to labor in the manufacturing sector an important conclusion is that unions raise prices less than was previously believed

portfolio selection under strict uncertainty a multi criteria methodology and its application to the frankfurt and vienna stock exchanges abstract in modern portfolio theory it is common practice to first compute the risk reward efficient frontier and then to support an individual investor in selecting a portfolio that meets his her preferences for profitability and risk potential flaws include a the assumption that past data provide sufficient evidence for predicting the future performances of the securities under consideration and b the necessity to mathematically determine or approximate the investor s utility function in this paper we propose a methodology whose initial phase filters portfolios that are inefficient from a historical perspective while this is consistent with traditional approaches the second phase differs from the standard approach as it uses a decision table constructed by considering multiple scenarios assuming strict uncertainty the table cells measure consequences by a multi criteria linear performance index of simulated future returns which avoids difficulties with performance ratios the real world applicability is illustrated through two studies based on data from the stock exchanges in frankfurt and vienna

capital skill complementarity and the interregional distribution of human capital in us manufacturing 1989 capital skill complementarity and the interregional distribution of human capital in us manufacturing applied economics vol 21 no 8 pp 1087 1098

the welfare implications of externalities and price elasticities for telecommunications pricing the efficiency implications of telecommunications service pricing are analogous to a puzzle whose parts are beginning to be assembled recently mitchell 1978 has examined the efficiency implications of alternative local service pricing approaches he contrasts the welfare effects of a flat monthly rate with measured service pricing under an optimal two part tariff with an access line charge and a per call charge daly and mayor 1980 have examined the efficiency implications of free directory assistance contrasting it to marginal cost pricing and found large welfare losses the efficiency implications of long distance telecommunications service which in 1975 accounted for almost one half of the bell system revenues remains to be placed in the puzzle the primary purpose of this paper is to examine the efficiency implications of the pricing of local service vis h vis conventional long distance service referred to as message telecommunications service mts which constitutes the bulk of long distance service excluded from this analysis are wats and private line service as demonstrated by rohlfs 1979 substantial cross subsidization occurs between local service which is priced approximately 50 below marginal cost and long distance which is priced two to three times above marginal cost nevertheless cross subsidization need not imply inefficiency in a second best pricing framework for several reasons baumol and bradford 1970 first subsidization of local service can be justified due to access externalities arising because the value to potential callers is not internalized in the subscriber s price second even in the absence of access externalities if the price elasticities of both services tend to be very inelastic cross subsidization may have negligible efficiency effects the optimal second best pricing approach depends critically on the deviation of price from marginal costs the extent of the access externality and the relative price elasticities for local and long distance service in this exercise the welfare effects are particularly sensitive to the price elasticity of mts service thereby justifying the empirical focus on the price elasticity of mts the mts demand relationship estimated in this paper contains advances in several respects first unlike previous pure time series or cross sectional studies 2 the data set consists of pooled quarterly data 1966 to 1978 for five southwestern states the analysis of intrastate long distance demand3 offers a much more robust data source than national interstate demand owing to the limited price variation in the latter the pooled model features polynomial distributed lags and an error structure which corrects for both autocorrelation and heteroskedasticity also the model includes a unique and superior measure of television advertising effects an index of gross rating points reflecting the actual frequency with which television advertising is viewed by the public the use of gross rating points avoids the distortion implicit in the substantial volume discounts reflected in expenditure data 4 the subsequent section outlines the simple theoretical model which is the basis for econometric estimation and the pooling techniques section iii reports the empirical results in section iv we examine the price elasticity implications for optimal pricing of mts service section v recapitulates the major conclusions and suggests directions for future research received for publication september 29 1980 revision accepted for publication april 20 1981 university of houston the author wishes to acknowledge the collaboration of bruce egan in the econometric modelling section of this paper in addition numerous helpful comments were provided by george daly thomas mayor jeffrey rohlfs william taylor and an anonymous referee i see rohlfs 1978 table iii 1 2 for a review see taylor 1980 and lowry 1976 3 taylor notes that from the view of demand the distinction between interstate and intrastate mts is purely artificial see taylor 1980 p 97 and table 5 1 4 comanor and wilson 1967 note that volume discounts may give rise to increasing marginal returns to advertising expenditures

optimal hedge ratios with risk neutral producers and nonlinear borrowing costs a new theory of hedging is derived assuming producers are risk neutral forward pricing is costly and borrowing costs are nonlinear the standard risk minimizing hedge ratio is derived when forward pricing is costless when the assumption of costless hedging is dropped high leveraged firms are shown to hedge more than do low leveraged firms if the value of capital is uncorrelated with output price firms are shown to hedge more as cash price variability increases thus the model can be consistent with what firms actually do

the effects of unions on employment and productivity an unresolved contradiction the evidence that unions substantially increase productivity is contradicted by the evidence that the effect of unions on employment is small it is shown in this paper that if the union is constrained by the firm s demand function and it is the efficiency units of labor that are in the demand function then essentially the only way to resolve this contradiction is for unions to raise the productivity of capital and not of labor under conditions where the substitutability between labor and capital is very limited but estimates of the substitutability parameter are near unity so that one of these effects must be wrong either unions do not substantially increase productivity or they substantially reduce employment

gender differences in marketing styles recent research has found that men trade stocks more frequently than women and receive a lower price as a result the behavioral finance literature attributes this greater trading activity to men s overconfidence women s lack of overconfidence and past agricultural economics research suggest the possibility that women may be better at marketing grain than men this article uses actual transactions of farmers marketing wheat and also finds that men trade more often than women women also sell two weeks later in the marketing year there is no direct effect of gender on price received but by storing longer women receive 1 4 cents bushel less than men on average in contrast to the arguments in previous research we argue that men s greater number of trades can be better explained by men enjoying trading rather than by overconfidence

demand and pricing of telecommunications services evidence and welfare implications although telephone pricing has received increasing attention in recent years the geographic patterns of telephone pricing and the corresponding economic consequences of those patterns have remained perplexing to consumers and policymakers and largely unaddressed by economists in this article we first specify a model of the demand for short intralata long distance calling we then draw upon data made available by the recent adoption of extended area service eas in four metropolitan areas to empirically measure the structure of inter exchange telephone demand given these estimates and a conceptual framework for analyzing the economic welfare effects we were able to quantify the consumer surplus effects of alternative pricing policies the empirical results indicate that consumer surplus is noticeably enhanced by adopting eas but the net economic welfare effects are shown to be sensitive to among other things the level of price cost margins prevailing prior to the implementation of eas

optimal procurement strategies for online spot markets abstract spot markets have emerged for a broad range of commodities and companies have started to use them in addition to their traditional long term procurement contracts forward contracts in comparison to forward contracts spot markets offer products at essentially negligible lead time but typically command a higher expected price for this added flexibility while also exhibiting substantial price uncertainty in our research we analyze the resulting procurement challenge and quantify the benefits of using spot markets from a supply chain perspective we develop and solve mathematical models that determine the optimal order quantity to purchase via forward contracts and the optimal quantity to purchase via spot markets we analyze the most general situation where commodities can be both bought and sold via a spot market and derive closed form results for this case we compare the obtained results to the reference scenario of pure contract sourcing and we include results for situations where the use of spot markets is restricted to either buying or selling only our approaches can be used by decision makers to determine optimal procurement strategies based on key parameters such as demand and spot price volatilities correlation between demand and spot prices and risk aversion the results of our analysis demonstrate that significant profit improvements can be achieved if a moderate fraction of the commodity demand is procured via spot markets the results also show that companies who use spot markets can offer a higher expected service level but that they might experience a higher variability in profits than companies who do not use spot markets we illustrate our analytical results with numerical examples throughout the paper

labour inputs substitution during corporate restructuring a translog model approach for us freight railroads after deregulation in 1980 competitive pressures forced the large us freight railroads to reduce costs and restructure resulting in an economic renaissance of the us railroad companies after years of poor financial conditions the most striking restructuring measure receiving much attention was dramatic labour downsizing until 2004 employment was reduced by 60 but other overlooked measures are the significant restructuring of workforce composition and important changes in railroads workplace organization practices and corporate culture to better understand this successful occupational restructuring i investigate labour inputs substitutional relationships by using a translog variable cost model labour is decomposed into six employee categories rather than traditional production nonproduction breakdown to estimate inputs elasticities of substitution the data investigated is a unique firm level dataset on the us freight class i railroads covering a 22 year period which allows this fine grained a

labor income uncertainty skewness and homeownership a panel data study for germany and spain abstract in this paper we empirically investigate the effect of labor income uncertainty on the probability of homeownership in germany and spain this study is motivated by two facts firstly theoretical models tend to provide ambiguous results on this issue secondly previous empirical evidence focuses exclusively on the us housing market to carry out our analysis we propose more precise income uncertainty measures based on panel data labor income equations we observe that households facing high levels of income uncertainty display a preference for renting while those located in more positively skewed income distributions show a greater propensity for homeownership

compensating wage differentials for schooling risk in denmark in this paper we analyse the association between wage differentials and risk using detailed information on length and type of education as seen in danish administrative registers our contribution to the literature is that we distinguish between transitory time series and permanent cross sectional income shocks and estimate the compensation for both sorts of risk we find that wage risk in a given education cell is associated with higher wages while skewness is associated with lower wages as a robustness check we see that ad hoc risk measures based on earnings mobility indicators confirm these findings

land allocation under uncertainty for alternative specifications of return distributions using the expected utility moment generating function approach a land allocation rule is derived which is both independent of the nature of the underlying distribution of each element in the choice set and accounts for all moments of that distribution this decision rule is applied to the choice between cotton and corn in the mississippi delta to demonstrate that consideration of just the first two moments of the distribution can often be unjustified and damaging empirically theoretically and in terms of the utility of the decision maker

substitution between production labor and other inputs in unionized and nonunionized manufacturing comment age points of the productivity decline after correcting faulty calculations in deriving a new price deflator errors in measuring the left hand side account for another 7 5 percentage points together they account for 56 5 of the observed decline this is a more modest accomplishment than the 92 claim of my earlier paper but still a substantial one in light of earlier research efforts such as stokes 1981 which could not explain any of the observed decline

hedging with commodity options when price distributions are skewed lapan moschini and hanson have demonstrated that commodity options can be useful for hedgers who face a symmetric price distribution and who wish to maintain a net open market position this is because options skew the distribution of profits to the right and such skewness typically increases expected utility in this paper i use standard comparative statics to show that options are relatively more valuable for reducing the skewness of a nonsymmetric price distribution depending on the direction of the skewness and the underlying price expectations hedgers may write options as well as purchase them

trends in the growth and distribution of skills in the u s workplace 1960 1985 using new measures of job skills and standard measures of education and earnings the authors examine the effects of changing occupational and industry employment patterns on the skill composition of work between 1960 and 1985 the results show a strong upgrading of cognitive and interactive skills combined however with a substantial slowdown in the rates of growth of those skills and a declining demand for motor skills the earnings mix of jobs did not show the same high correlation with employment growth as skill and education levels because high wage low skill jobs declined in the goods industries while low wage jobs requiring at least moderate skill levels grew rapidly in the services

more reasons why farmers have so little interest in futures markets the use by farmers of futures contracts and other hedging instruments has been observed to be low in many situations and this has sometimes seemed to be considered surprising or even mysterious we propose that it is in fact readily understandable and consistent with rational decision making standard models of the decision about optimal hedging show that it is negatively related to basis risk to quantity risk and to transaction costs farmers who have less uncertainty about prices and those with a diversified portfolio of investments have lower optimal levels of hedging if a farmer has optimistic price expectations relative to the futures market the incentive to hedge can be greatly reduced and finally farmers who have low levels of risk aversion have little to gain from hedging in terms of risk reduction in that the certainty equivalent payoff at their optimal hedge may be little different than the certainty equivalent under zero hedging these reasons are additional to the argument of simmons 2002 who showed that if capital markets are efficient farmers can manage their risk exposure through adjusting their leverage obviating the need for hedging instruments

rejecting capital skill complementarity at all costs any serious empirical study of factor substitutability has to allow the data to display complementarity as well as substitutability the standard approach reflecting this idea is a translog specification this is also the approach used by numerous studies analyzing the relative capital skill complementarity hypothesis formulated by griliches 1969 according to this hypothesis the degree of substitutability between skilled labor and capital is lower than that for unskilled labor and capital yet the results of empirical studies investigating this hypothesis are controversial this paper offers a straightforward explanation using a translog approach reduces the issue of actor substitutability or complementarity to a question of cost shares our review of translog studies mentioned in hamermesh s 1993 summary on the demand for heterogeneous labor demonstrates that this argument is empirically relevant all these studies can be reconciled with each other on the basis of the cost share argument

union firm efficient bargaining and test of oligopolistic conduct this paper applies a production function approach to the analysis of imperfection in product and factor markets and develops a test of efficient bargaining for wage and employment determination based on a translog function defined at the firm level estimates for the belgian chemical industry are consistent with the existence of product market power which is significantly eroded by union wage rents

social welfare of alternative controlled price policies recent developments in social welfare analysis provide insights into the selection of price policies in the presen t paper a ces social welfare function and a weighted average of utilitarian and leximin rules are used to identify optimal producer prices in an economy where government is the price setter and agents are risk averse the analysis distinguishes between the interests of commercial producers peasant producers consumers and taxpayers a n application to zimbabwe indicates that a maize producer price in the low medium to medium portion of the historical range would be social ly optimal if egalitarian preferences are moderate this outcome is somewhat insensitive to group weighting schemes and to interpersonal utility correspondences copyright 1993 by mit press

union nonunion compensation differentials across plant sizes evidence from cps 1983 previous empirical work on the relationship between plant size and union nonunion differentials has focused either on wages podgursky 1986 or benefits bramley wunnava and robinson 1989 freeman 1981 this note extends this research by simultaneously focusing on both wages and benefits there are several arguments that can be made in explaining union nonunion differentials across plant sizes 1 union threat effects 2 efficiency wage effects and 3 wage dispersion effects our study focuses on measuring the union nonunion differential in total compensation for this end estimates of total compensation are obtained using mellow s suggestion 1982 for combining hourly wage information with qualitative data on pensions and health insurance and ross s imputations 1989 for holidays and vacations benefits our results based on the may 1983 cps supplemented by bls data on pensions health insurance holidays and vacation benefits indicate significant union nonunion total compensation differentials exist only for workers in establishments with less than 500 workers these results are consistent with podgursky s wage differential findings

household portfolio diversification a case for rank dependent preferences the proliferation of novel preference theories in financial economics is hampered by a lack of non experimental evidence and by the theories additional complexity which has not been shown to be critical in applications in this article i present arguments in support of preferences with rank dependency using the survey of consumer finances data i document two widespread patterns inconsistent with expected utility i many households simultaneously invest in well deversified funds and in poorly diversified portfolios of stocks and ii some households with substantial savings do not invest anything in equities i show that portfolio choice models with rank dependent preferences plausibly parameterized and under fully rational assumptions are quantitatively consistent with the observed diversification these results call for further efforts to integrate the models of rank dependent preferences in portfolio theory and asset pricing the decision theoretic literature has long acknowledged the shortcomings of the expected utility theory of von neumann and morgenstern 1944 several generalizations of the theory are inspired by the experimental evidence and aimed at improving its descriptive accuracy however there are few applications of new models of preferences in finance and expected utility continues to dominate the field 1 two principal hurdles slow the proliferation of novel preferences in financial economics first the lack of empirical non experimental or field data confirming that the behavior motivating non expected utilities is widespread outside the laboratory settings second the additional and often significant complexity of the alternative preferences which has not been shown to be critical in applications where the models based on expected utility fall short of reasonable predictions this article presents empirical and theoretical this paper was previously circulated under the title household portfolio diversification the paper has benefited from the comments of shlomo benartzi luca benzoni markus brunnermeier john dickhaut maria perozek raj singh hersh shefrin and workshop participants at minnesota finance bag lunch 2003 wharton conference household financial decision making and portfolio choice and 2003 summer meetings of econometric society i would like to thank cam harvey the editor and an anonymous referee for many helpful comments and suggestions a special thanks to jack kareken for comments and editorial help on an earlier draft i am grateful to donna zerwitz for editorial assistance the views expressed herein are those of the author and not necessarily of the federal reserve bank of minneapolis or the federal reserve system all errors and omissions are the sole responsibility of the author address correspondence to valery polkovnichenko finance 3 122 csom 319 19 th

the shape of utility functions and organizational behavior based on measurements among 332 owner managers we investigate how theglobal shape of the utility function i e s shaped versus concave or convex over the total range of outcomes relates to choice behavior we find that the global shape of the utility function differs across decision makers about one third of the owner managers exhibit an s shaped utility function and that the global shape is linked to organizational behavior i e the production system employed a result that does not change when using different methods to identify the decision maker s global shape of the utility function the decision maker s risk attitude risk averse or risk seeking does not affect the choice of the production system whereas the degree of risk aversion based on thelocal shape of the utility function may be important in explaining owner managers trading behavior pennings and smidts 2000 more structural organizational behavior appears to be linked to theglobal shape of the utility function

customer discrimination and affirmative action i introduction beginning with the work of becker 1957 economists have been concerned with the relationship between competitive market forces and the persistence of labor market discrimination 1 a major insight of becker and the literature that followed is that competition could tend to eliminate discriminatory pay differentials if competitive forces do eliminate discrimination then empirical findings of persistent discrimination are either a result of faulty testing or market imperfections economic analysis of the link between competition and discrimination depends on the origins of prejudice becker identified at least three possible sources employers co workers and consumers 2 in each of these instances the group against which prejudice is directed e g women or minorities which will be termed minorities in this paper may be able to escape discrimination first minorities can work for nondiscriminatory employers if there are any moreover stiglitz 1973 shows that with constant returns to scale such employers will take over markets from the discriminators eliminating any pay gap based on prejudice 3 second if there is co worker prejudice then minorities can work in segregated firms which under constant returns to scale may have a cost advantage over integrated or all majority firms again discrimination will be driven away 4 third minorities can theoretically escape customer discrimination by specializing in the production of goods for which there is no contact between producers and consumers a case discussed by cain 1986 while competitive forces may in some cases erode discriminatory wage differentials the rate of decline of race and sex wage differentials has evidently not been rapid enough in the eyes of policymakers u s anti discrimination policy has been guided by two major vehicles title vii of the 1964 civil rights act and the office of federal contract compliance programs ofccp 5 the equal employment opportunity commission eeoc was created to enforce title vii and is empowered to aid plaintiffs or bring suit itself against employers the commission monitors the employment practices of federal contractors not only are contractors barred from discrimination against protected groups these firms are also required to take affirmative action not to discriminate the purpose of this paper is twofold first it demonstrates that in a general equilibrium framework the case of customer discrimination is theoretically distinct from employer or co worker prejudice in particular while constant returns to scale and the existence of nondiscriminatory firms can eliminate the latter two forms of discrimination customer discrimination may persist even under such conditions the persistence of discriminatory wage differentials is shown to depend on consumer demand technology and the relative size of the minority labor force 6 second the general equilibrium framework is then used to evaluate the impact of government anti discrimination policy where customers are the source of discrimination it is shown that if the government requires equal pay and proportional representation for minorities then the resulting allocation of resources will under particular assumptions be the same as if customers did not discriminate i then contrast these theoretical results with the predicted general equilibrium impact of affirmative action when there is employer or co worker prejudice among previous general equilibrium models of affirmative action welch 1976 assumed no discrimination while freeman 1978 did not specify the source of discrimination it is shown here that the source of prejudice markedly affects one s conclusions about affirmative action further even in some cases where segregation has eliminated discriminatory wage differentials the introduction of affirmative action has allocative effects finally evidence from studies evaluating the impact of affirmative action is used to distinguish among the various equilibrium models

futures hedging under price basis and production risk we consider the hedging problem of a firm that has three sources of risk price basis and yield uncertainty an exact solution for the optimal futures hedge is derived under the assumption that the three random variables are jointly normally distributed and that utility is of the cara type unlike the mean variance approximation applied in previous research we show that the optimal hedge does depend on risk attitudes even when the agent perceives the futures price as being unbiased the theoretical results are applied empirically to the problem of hedging soybean production in iowa the exact solution relying on cara and normality is compared with numerical solutions under lognormal distributions and crra utility

unionism and employment behaviour although there exists a large literature on the effects of trade unions upon wages there is no published work that uses microeconomic data on establishments to examine the employment consequences of unionism this paper addresses this issue with a recent british data set and shows that even after the addition of a substantial set of control variables there is a strong association between poor employment performance and the presence of trade unions the union employment growth differential is estimated at approximately 3 percent per annum copyright 1991 by royal economic society

paralegals and substitution among labor inputs in the law firm despite the recent interest in economic analysis of the law firm and the market for legal services 1 little attention has been given by economists to a phenomenon of increasing importance in the markets for inputs to the production of legal services the rise of the paralegal to illustrate between 1972 and 1977 the number of practicing attorneys in the u s increased by 41 percent but the number of paraprofessionals in legal services increased by 135 percent if we look at all law firms in the u s we find the share of labor cost paid to paralegals almost doubled in those five years increasing from 3 7 percent to 6 7 percent on the other hand the cost share of salaried associate lawyers was stable over the same period this raises the questions of how easily substitutable the various labor inputs are for one another in this paper we examine this issue by using a short run labor substitution model estimating cost share equations derived from a translog labor price function data from the 1977 census of service industries are used to derive quantity and price measures for three types of labor inputs associate lawyers paraprofessionals and all others for law partnerships in 65 standard metropolitan statistical areas the primary result is that paralegals seem more closely substitutable with other workers secretarial clerical messengers than with associate lawyers suggesting that wages and employment of lawyers are unlikely to have been significantly affected by the influx of paralegals

substitution between production labor and other inputs in unionized and non unionized manufacturing the ease of substitution between labor and other factors of production is an important determinant of the elasticity of demand for labor and thus of the economic effects of unionism all else the same the greater the elasticity of substitution the greater is the elasticity of derived demand and the greater the displacement of labor for a given union induced wage increase in sectors where this elasticity is large unions are likely to be relatively weak and able to win only slight wage gains freeman and medoff 1981 and forthcoming or if they win large gains will have to pay a high price in terms of lost jobs in the sectors where the elasticity is small unions may be able to extract a substantial wage premium at little cost in terms of employment moreover as a simple general equilibrium model indicates the elasticity of substitution between labor and other factors in the unionized sector is a key parameter in determining the impact of the iiunion wage effect on the earnings of nonunion workers and on the efficiency of the economy johnson and mieskowski 1970 despite the importance of the elasticity of labor demand for an analysis of unionism little attention has been given to the absolute and relative magnitude of this elasticity under collective bargaining while there is some discussion of technological change and the substitution of capital and nonproduction workers for organized production workers in the institutional literature e g slichter 1941 slichter healy and livernash 1960 bok and dunlop 1970 modern econometric work provides no estimates of the relevant parameters as a result johnson and mieskowski 1970 rees 1963 lewis 1964 and others have been forced to evaluate union effects with guesstimates of the elasticities of concern in union settings this paper attempts to fill some of the gap in our knowledge by providing estimates for u s manufacturing of the constant output elasticity of demand for unionized and nonunionized production workers and of the elasticity of substitution between these workers and other inputs the analysis concentrates on what we call the relative inelasticity hypothesis which states that the demand for production workers will be more inelastic in the presence of a union for two reasons the likelihood that unions have organized and survived in sectors with low elasticities and the effects of various contract provisions on the ability of management to substitute other factors for production labor the study is divided into four sections section i develops the rationale for the relative inelasticity hypothesis and describes the nature of the empirical analysis conducted to test its validity the second section uses a 1972 state by 2 digit standard industrial classification sic industry data file for manufacturing to estimate the elasticity of substitution between production labor and both nonproduction labor and capital in the union and nonunion sectors of u s manufacturing industries section iii provides estimates based on a 1968 72 sample of manufacturing establishments of the elasticity of substitution between production and nonproduction labor the only two inputs for which information is available the final section briefly summarizes the findings and discusses their implications for understanding the impact of trade unionism on the u s economy to preview the ensuing discussion our main conclusion is substitution between production labor and other inputs is generally lower in union received for publication march 6 1978 revision accepted for publication august 17 1981 both authors are with harvard university and the national bureau of economic research supported by u s department of labor grant no j 9 m 6 0094 national science foundation grant no apt77 16279 and the national bureau of economic research under its program of research on labor economics we are especially grateful to jane mather for her invaluable assistance on this project and to greg bialecki charles brown gary chamberlain kathy coons jon fay martin van denburgh and lori wilson for their significant contributions the study has not been reviewed by the board of directors of the national bureau

new indices of money supply and the flexible laurent demand system the article begins by surveying the existing results on the new divisia monetary aggregates charts display the differences in behavior between the divisia aggregates and the federal reserve s official simple sum monetary aggregates the article then compares system wide fit for the simple sum and divisia monetary aggregates when used as data in the joint estimation of a system of demand equations the demand system is derived from a new laurent expansion approximation to the reciprocal indirect utility function the laurent expansion provides a better behaved remainder term than that of the more commonly used taylor series the results favor the divisia aggregates

portfolio theory and the demand for futures the case of california cotton this paper examines the simultaneous choice of cropping patterns and futures positions it derives the demand for hedging as a function of the price of a hedge and the crop choice set it estimates these functions for california cotton farmers it finds that both the costs of hedging and the opportunity to diversify risk by growing other crops substantially change the optimal hedge for california cotton farmers

necessary conditions for the capm abstract the general restrictions on all economic primitives i e a endowments b preferences and c asset return distributions that yield the capm under the expected utility paradigm are provided these results are then used to derive the class of restrictions on preferences and the distribution of asset returns alone that provides the capm we also show that the conditions that provide the capm and derived preferences over mean and variance are equivalent consequently this paper also resolves the question of when mean variance maximization is consistent with expected utility maximization journal of economic literatureclassification numbers g12 g11 d50

revisiting the determinants of futures contracts success the role of market participants the chicago mercantile exchange introduced a futures contract for distillers dried grains ddgs in early 2010 but the market became inactive only four months after its inception while many new futures contracts do not develop into high volume traders interest from ddg cash market participants indicated that this contract could be successful prompted by the unexpected lack of trading activity in this new futures market we empirically revisit the question of what factors contribute to a futures contract s success and extend the literature by investigating the roles of market participants and the significance of supporting futures markets estimation results indicate that the market participant type hedger or speculator affects futures contract trade volume more importantly we find that the viability of new futures contracts for commodities that are jointly produced with other commodities is impacted by hedgers trade volume of the related futures contract these results provide important additions into the portfolio of indicators used by commodity exchanges to more cost effectively evaluate new futures contract products

optimising criminal behaviour and the disutility of prison we use rich microdata on bank robberies to estimate individual level disutilitiesities of imprisonment the identification rests on the money versus apprehension trade off that robbers face inside the bank when deciding whether to leave or collect money for an additional minute the distribution of the disutility of prison is not degenerate generating heterogeneity in behaviour our results show that unobserved heterogeneity in robber ability is important for explaining outcomes in terms of haul and arrest furthermore higher ability robbers are found to have larger disutilities suggesting that increased sentence lengths might effectively target these more harmful criminals

what determines the elasticity of substitution between capital and labor a literature review this paper provides the first comprehensive review of the empirical and theoretical literature on the determinants of the elasticity of substitution between capital and labor our focus is on the two input constant elasticity of substitution ces production function we start by presenting four concise observations that summarize the empirical literature on the estimation of motivated by these observations the main part of this survey then focuses on potential determinants of capital labor substitution we first review several approaches to the microfoundation of production functions where the elasticity of substitution eos is treated as a purely technological parameter second we outline the construction of an aggregate elasticity of substitution aes in a multi sectoral framework and investigate its dependence on underlying intra and inter sectoral substitution third we discuss the influence of the institutional framework on the extent of factor substitution overall this survey highlights that the effective elasticity of substitution ees which is typically estimated in empirical studies is generally not an immutable deep parameter but depends on a multitude of technological non technological and institutional determinants based on these insights the final section identifies a number of potential empirical and theoretical avenues for future research

economic behavior under uncertainty a joint analysis of risk preferences and technology a method is developed to estimate jointly risk preferences and technology under general conditions the approach is illustrated in an application to the analysis of u s corn soybean acreage decisions over time the results provide useful information on the nature of farmers risk preferences and on the influence of price risk and production risk on acreage allocation and farmers welfare copyright 1996 by mit press

an economic analysis of factor usage and workplace regulation reply safety in the workplace has long been a subject of interest for economists much of this attention has focused on the presence of risks on the job and the tendency of workers and others to underestimate these risks adam smith 16 96 7 notes this optimism and as george stigler 19 points out jevons felt that workplace hazards were ignored by those most directly concerned this lack of faith in the market to provide adequate safety or to compensate those who face such risks is evident in the law regulating the workplace primarily workers compensation wc and the occupational safety and health act osha these policies are in the judgment of many modern economists justified by the misperception of risks 5 12 13 however other economists have argued that despite their intentions such laws may not have one of the primary effects they are directed to accomplish the reduction of workplace accidents relatively little research has been devoted to another aspect of safety regulation its cost perhaps because these costs are thought to be very small 2 it is on this issue that this paper focuses what is the impact of workplace regulation on firm decision making to accomplish this a model is developed in section ii which examines the impact on a firm s factor choices attributable to the imposition of workplace safety regulation the theory examines wc and osha both singly and jointly and their effects on the level of and changes in relative factor usage these considerations form the bulk of section iii this model yields some interesting conclusions about the effects of regulation in the workplace the primary implication of the theory is that all increases in safety are paid for through lowered output and factor employment moreover this result holds true whether the additional safety is the product of direct safety regulation osha or through indirect forms of regulation like wc these results are possibly more striking given the findings of empirical work done on the impact of wc and osha on safety this body of research has to

farmers long term investment decisions a study of sri lankan rubber smallholders planting and replanting of perennial crops confronts small farmers with a long term investment decision in this study we analyse the behaviour of rubber smallholders in sri lanka when faced with a replacement decision an intertemporal profit maximizing model maximizing discounted stream of expected future net revenues predicts behaviour of larger hired labour using farmers quite well the model can also be extended successfully to smaller family farms when a lower than market wage rate is imputed to family labour to better reflect opportunity cost of labour and risk considerations are incorporated in relatively simple fashion the difference between a cash investment and a labour investment is crucial for the poorer family farmers and an appropriate cash subsidy can play a vital role in inducing them to undertake long term investments

the demand for local telephone service a fully discrete model of residential calling patterns and service choices we present an empirical model of households choices among local telephone service options for example between flat rate and measured service and the interrelation of these choices with the number and average duration of local calls households make at each time of day to each geographical zone using a nested logit model with estimation performed on a randomly selected subset of the households calling patterns we calculate elasticities of demand for each local service option number of calls average duration and revenues with respect to the fixed monthly charges and the usage charges for calling under each option we find moderate price elasticities of number of calls with respect to usage charges for households subscribing to measured service nevertheless raising usage charges has a negligible effect on revenues since a sufficient number of households either originally subscribe to flat rate service or convert to flat rate service in response to higher usage charges we find a high elasticity of demandfor each service option with respect to itsfixed monthlyfee this indicates high substitutability among service options the shift among service options induces new calling patterns which wefind to be a small but not negligible indirect effect e most telephone operating companies offer residential customers several options for local service there are two general categories of service flat rate service under which a household can for a fixed monthly charge make an unlimited number of calls within a specified geographical area and measured service for which the household pays a lower fixed monthly fee but can make only a specified number or dollar value of calls at no extra charge after which charges are incurred for additional calls various flat rate services differ in the size of the geographical area in which calling is at no extra charge with higher monthly fees for larger areas measured services differ with respect to the threshold number or dollar value of calls beyond which the customer is charged

tri criterion inverse portfolio optimization with application to socially responsible mutual funds we present a framework for inverse optimization in a markowitz portfolio model that is extended to include a third criterion the third criterion causes the traditional nondominated frontier to become a surface until recently it had not been possible to compute such a surface but by using a new method that is able to generate the nondominated surfaces of tri criterion portfolio selection problems we are able to compute via inverse optimization the implied risk tolerances of given funds that pursue an additional objective beyond risk and return in applying this capability to a broad sample of conventional and socially responsible sr mutual funds we find that after the screening process there appears to be no significant di erence between how assets are allocated in socially responsible and conventional mutual funds which is likely to be di erent from what most sr investors would expect

portfolio selection and skewness evidence from international stock markets abstract this paper finds that the returns of the world s 14 major stock markets are not normally distributed and that the correlation matrix of these stock markets was stable during the january 1988 december 1993 time period polynomial goal programming in which investor preferences for skewness can be incorporated is utilized to determine the optimal portfolio consisting of the choices of 14 international stock indexes the empirical findings suggest that the incorporation of skewness into an investor s portfolio decision causes a major change in the construction of the optimal portfolio the evidence also indicate that investors trade expected return of the portfolio for skewness

the impact of unionization on motor carrier costs i introduction the increasingly competitive markets fostered by the motor carrier act of 1980 have forced motor carriers to focus on cost saving strategies intended to reduce operating miles fuel consumption and capital and labor expenses there are two reasons unions firms may be at a competitive disadvantage in these efforts first although the union nonunion wage differential has decreased following regulatory reform rose 1987 and hirsch 1988 find that union firms still pay higher wages second managers of unionized firms may have less flexibility in the use of inputs since union work rules restrict the activities and substitutability of drivers terminal workers and terminal facilities indeed harrington 1987 reports that post 1980 trucking expenses are still 40 higher for unionized motor carriers than for nonunion firms unionization may affect carrier cost both by increasing the price of labor and by potentially affecting cost function parameters if union rules make labor less productive the entire cost function will shift upwards for a given set of factor input prices further freeman and medoff 1982 argue that work rules may be expected to result in reduced elasticities of substitution between labor and other inputs in the unionized setting indeed they find that substitution between production labor and other labor in manufacturing is generally lower in unionized settings the impact of unionization on production has been investigated in industries such as construction coal mining hospitals and the cement industry by allen 1984 1986a 1986b byrnes et al 1988 and clark 1980a 1980b the results have been inconclusive with unionized firms being more productive than nonunion firms in some instances and less productive in others studies such as allen 1986c and addison and hirsch 1989 have utilized production function methodologies that use restrictive functional forms which impose homogeneity and identical elasticities of substitution between pairs of inputs allen 1986c examines the relative efficiency of union and nonunion firms with a translog cost function allowing for union effects using intercept and slope parameters that vary by union status in his study of different types of construction projects he finds significant differences between the cost functions for union and nonunion firms but no evidence of the inelasticity of factor substitutions as hypothesized by medoff and freeman in fact his estimates of factor demand elasticities show no discernible pattern for union versus nonunion firms leading him to conclude that work rules do not have the anticipated impact on elasticity the purpose of this study is to test whether unionization impacts motor carrier costs and if so to determine the direction of the impact of particular interest is whether the work rules imposed by the teamster s union have had a significant impact on factor substitutability in unionized firms as argued by freeman and medoff 1982 friedlaender and spady 1981 daughety et al 1985 mcmullen and stanley 1988 grimm et al 1989 and ying s 1990 studies of motor carrier industry costs have used translog cost functions which implicitly assume that union and nonunion cost functions arise from the same production technology this is equivalent to accepting the hypothesis that unionization does not affect the production structure of motor carrier firms if unionization does affect a firm s production process the results from these studies could be biased accordingly this study uses a translog cost function to test for differences in the cost structure of union and nonunion carriers not only is the translog cost function standard in the motor carrier literature permitting comparison of these results with those of previous work it also allows the flexibility necessary to examine the differential impact of unions on cost function parameters and elasticities of substitution between factors

selecting a portfolio with skewness recent evidence from us european and latin american equity markets abstract polynomial goal programming in which investor preferences for skewness can be incorporated is utilized to determine the optimal portfolio from latin american us and european capital markets the empirical findings suggest that the incorporation of skewness into an investor s portfolio decision causes a major change in the resultant optimal portfolio the empirical evidence indicates that investors do trade expected return of the portfolio for skewness

optimal fuel mix in chp plants under a stochastic permit price risk neutrality versus risk aversion abstract this paper studies the optimal fuel mix of a chp producer under emission permit price risk the producer s multi fuel plant uses two co2 intensive fuels and one clean fuel using a mean variance framework we develop three models the models are divided into spot models risk neutral and risk averse cases and a forward model risk averse case we derive the effects of price risk on optimal fuel use an increase in price risk can in fact increase the use of co2 intensive fuel in the spot model in the forward model the production and financial decisions are separate we also evaluate the risk bearing behavior of seven finnish chp producers we found that risk neutrality describes behavior better than risk aversion

portfolio selection in the mean variance model a note a little recognized feature of the mean variance portfolio selection model is that induced preferences for asset holdings are not necessarily monotone more of an asset or portfolio is not necessarily better even if the asset or portfolio has positive expected return the model predicts that an investor typically wants only a limited number of shares of an asset and beyond that the increase in mean return from costlessly getting more of an asset is not sufficient to compensate for the increased risk this is reasonable if the model describes a market for contracts with unlimited liability where total returns may be negative e g they may be normally distributed it is unreasonable however if the model is used to describe a stock market with limited liability in that case it is desirable to impose conditions that ensure that there is no upper limit to how much of an asset or portfolio the investor wants the sharpest possible conditions are identified in section i since portfolio preferences are not monotone global satiation is possible again this is unrealistic when liability is limited satiation is bothersome also because it may lead to nonexistence of equilibrium in black s 4 capm without a riskless asset as demonstrated in nielsen 9 uniqueness of equilibrium in capm is investigated in nielsen 10 section i identifies the exact conditions under which global satiation does or does not occur the conditions compare the maximum ratio of mean to standard deviation of total return available from the assets with the investor s limiting degree of risk aversion as measured by the slope of his or her indifference curves at high levels of risk an optimal portfolio may or may not exist in the portfolio selection problem depending on the asymptotic slopes of the efficient frontier and the investor s indifference curves section ii identifies the exact conditions mean variance behavior can arise from expected utility maximization based on normal distributions in that case the conditions for nonsatiation and for existence of optimal portfolios can be stated in terms of the von neumannmorgenstern utility function section iii relates the relevant properties of the utility function for standard deviation and mean to properties of the von neumann morgenstern utility function