technical change land quality and income distribution a general equilibrium analysis this paper investigates the distributional effects of technical progress in agriculture a small computable general equilibrium model is developed in which agricultural production occurs in two environments with fixed land resources of different quality the analytical structure permits not only the rate but also the factor biases of technical change to differ between environments distributional results are generated for several classes of households distinguished both by their ownership of factors and by their consumption patterns the results demonstrate that technical change produces distributional outcomes which are highly sensitive to its factor biases and to prior differences in land quality

portfolio choice and liquidity constraints we study the infinite horizon model of household portfolio choice under liquidity constraints and revisit the portfolio specialization puzzle we show why the puzzle is robust to several model variations and argue that positive correlation between earnings shocks and stock returns is unlikely to provide an empirically plausible resolution we find that relatively small fixed costs for stock market entry are sufficient to deter stockholding because for a plausible range of parameter values households can achieve desired consumption smoothing with small or zero holdings of stocks such costs could arise from informational considerations sign up fees and investor inertia

differential technology adoption and income distribution in pakistan implications for research resource allocation a multi market model of technological change in food production is used to simulate the long run income distributional implications of differential diffusion of currently available wheat technologies in pakistan the results indicate that a research agenda emphasizing technologies suited to pakistan s favored production environments would enhance overall production without compromising inter group equity it is found that when commodity prices are market determined net consuming households are the major beneficiaries of technological change however in the more common situation of government intervention in markets for staple foods net producing households are the principal beneficiaries of technological change

rural infrastructure transactions costs and market participation in kenya abstract we develop a conceptual framework for quantifying fixed transactions costs facing semisubsistence households using household survey data from a sample of 324 kenyan maize farmers we jointly estimate household supply and demand schedules and transactions costs econometric results indicate that on average the ad valorem tax equivalent of fixed transactions costs for households in our sample is 15 additional analysis indicates that economic isolation is positively associated with the size of transactions costs to the best of our knowledge ours are the first empirical estimates of the magnitude of fixed transactions costs for agricultural households in developing countries

cyclical dynamics in idiosyncratic labor market risk is individual labor income more risky in recessions this is a difficult question to answer because existing panel data sets are so short to address this problem we develop a generalized method of moments estimator that conditions on the macroeconomic history that each member of the panel has experienced variation in the cross sectional variance between households with differing macroeconomic histories allows us to incorporate business cycle information dating back to 1930 even though our data do not begin until 1968 we implement this estimator using household level labor earnings data from the panel study of income dynamics we estimate that idiosyncratic risk is i highly persistent with an annual autocorrelation coefficient of 0 95 and ii strongly countercyclical with a conditional standard deviation that increases by 75 percent from 0 12 to 0 21 as the macroeconomy moves from peak to trough

portfolio choice in the presence of background risk in this paper we focus on how the presence of background risks from sources such as labour and entrepreneurial income influences portfolio allocations this interaction is explored in a theoretical model that is calibrated using cross sectional data from a variety of sources the model is shown to be consistent with some but not all aspects of cross sectional observations of portfolio holdings the paper also provides a survey of the extensive theoretical and empirical literature on portfolio choice

the cyclical and secular behaviour of the labour input comparing efficiency units and hours worked summary a monthly labour input series designed to correct for the fact that all hours worked are not of the same quality is constructed and its properties compared with unadjusted hours worked this efficiency units series is constructed from bls data on hours worked and earnings by age and sex the cyclical fluctuations displayed by the efficiency units series are smaller on average than those displayed by hours worked although the difference is not large however the secular behaviour of the series is quite different hours worked per capita displays a significant positive trend while efficiency units per capita does not

sticky information in general equilibrium this paper develops and analyzes a general equilibrium model with sticky information the only rigidity in goods labor and financial markets is that agents are inattentive sporadically updating their information sets when setting prices wages and consumption after presenting the ingredients of such a model the paper develops an algorithm to solve this class of models and uses it to study the model s dynamic properties it then estimates the parameters of the model using u s data on five key macroeconomic time series it finds that information stickiness is present in all markets and is especially pronounced for consumers and workers variance decompositions show that monetary policy and aggregate demand shocks account for most of the variance of inflation output and hours jel e30 e10

estimating the benefits of plant breeding research methodological issues and practical challenges impact assessment studies consistently show that the benefits generated by plant breeding are large positive and widely distributed numerous case studies have concluded that investment in plant breeding research generates attractive rates of return compared to alternative investment opportunities that welfare gains resulting from the adoption of modern varieties mvs reach both favoured and marginal environments and that benefits are broadly shared by producers and consumers but just how reliable are the results of studies that estimate the benefits of plant breeding research this article reviews methods used to estimate the benefits of plant breeding research and discusses theoretical and empirical issues that often receive inadequate attention in applied impact assessment work our objective is not to question the validity of the theoretical frameworks commonly used to estimate the benefits of plant breeding research but rather to examine problems that can arise when the widely accepted theoretical frameworks are used for empirical analysis most of these problems can be grouped into three basic categories 1 problems associated with measuring adoption and diffusion of mvs 2 problems associated with estimating benefits attributable to adoption of mvs and 3 problems associated with assigning credit among the various plant breeding programmes that participated in developing the mvs

optimal portfolio choice with wash sale constraints abstract we analytically solve the portfolio choice problem in the presence of wash sale constraints in a two period model with one risky asset our results show that wash sale constraints can heavily affect portfolio choice of investors with unrealized losses the trading behavior of such investors is to a large extent driven by the desire to realize those losses either immediately by sharply decreasing the holding of assets carrying unrealized losses or indirectly by increasing such holdings in order to prepare for a decrease in a future period to earn the tax rebate payment our findings are robust to increasing the number of trading dates and introducing a second risky asset and a correlation structure

peanut research and poverty reduction impacts of variety improvement to control peanut viruses in uganda a procedure is developed and applied for predicting ex ante impacts of agricultural research on aggregate poverty using as an example the poverty reducing impact of peanut research in uganda market level information on economic surplus changes is combined with a procedure for allocating income changes to individual households characteristics of farmers that affect their likelihood of technology adoption are used to create a technology adoption profile associated changes in poverty resulting from adoption are computed using poverty indices predicted income changes at the household level are aggregated to the market level and reconciled with calculations of economic surplus changes

saving and liquidity constraints this paper is concerned with the theory of saving when consumers are not permitted to borrow and with the ability of such a theory to account for some of the stylized facts of saving behavior the models presented in the paper seem to account for important aspects of reality that are not explained by traditional life cycle models copyright 1991 by the econometric society

modeling the impact of agricultural growth and government policy on income distribution in india this article uses a limited general equilibrium model to investigate the growth and equity effects of a variety of economic and technical changes and selected agricultural policies in india it explores how changes in food prices rural wages and farm profits associated with the green revolution period affected income distribution between net buyers and sellers of food the model shows that income gains from the green revolution initially accrued to the wealthier rural groups but that after 1972 73 they were transferred to urban consumers and that by 1980 81 the per capita incomes of poor and wealthier rural groups alike were barely above their respective 1960 61 levels the model is also used in counterfactual analysis of the impact of changes in technological demographic investment taxation and income redistribution variables its findings indicate the importance of trade policies for the nature of the equity outcomes from agricultural growth and suggest that a reduction in population growth and an increase in nonagricultural employment and income are required to convert agricultural growth into reduced rural poverty

a news utility theory for inattention and delegation in portfolio choice recent evidence suggests that investors are inattentive to their portfolios and hire expensive portfolio managers this paper develops a life cycle portfolio choice model in which the investor experiences loss averse utility over news and can ignore his portfolio in such a model the investor prefers to ignore and not rebalance his portfolio most of the time because he dislikes bad news more than he likes good news such that expected news causes a first order decrease in utility consequently the investor has a first order willingness to pay a portfolio manager who rebalances actively on his behalf moreover the investor can diversify over time and his consumption aligns with predictions of mental accounting i structurally estimate the preference parameters by matching stock shares and stock market non participation over the life cycle my parameter estimates are in line with the literature generate reasonable intervals of inattention and simultaneously explain consumption and wealth accumulation over the life cycle here it matters that news utility preserves first order risk aversion even in the presence of stochastic labor income which also causes stock shares to rise in wealth

understanding why high income households save more than low income households abstract we use a calibrated life cycle model to evaluate why high income households save as a group a much higher fraction of income than do low income households in us cross section data we find that 1 age and relatively permanent earnings differences across households together with the structure of the us social security system are sufficient to replicate this fact 2 without social security the model economies still produce large differences in saving rates across income groups and 3 purely temporary earnings shocks of the magnitude estimated in us data alter only slightly the saving rates of high and low income households

life cycle portfolio choice the role of heterogeneous under diversification the empirical work on household portfolio choice documents two facts one the stock market participation rate is low and hump shaped over the life cycle two the conditional share of stocks is also low but does not appear to change much during the life cycle in contrast the standard life cycle portfolio choice model predicts high and monotonically increasing participation rates and conditional stock shares that are low and exhibit dramatic changes with age in this paper i consider a number of extensions to this basic framework i find that a small per period participation cost is needed to generate a hump shaped life cycle profile of participation rates under a realistic calibration the quantitative effect is minor progressive social security and the assumption that the risk of stock portfolios is declining in household wealth as a consequence of better diversification opportunities an assumption that has some empirical support though provide substantial amplification and significantly improve the ability of the model to match the data under diversification also reduces the average portfolio share of stocks conditional on participation and together with the intergenerational transmission of wealth makes it insensitive to age consistent with the empirical evidence

welfare effects of maize technologies in marginal and high potential regions of kenya this paper describes the findings of a study that used a multi market model to assess the potential impact of improved maize technologies on the welfare of various types of rural and urban households in kenya the modelling results indicate that technologies developed for high potential regions are likely to have more profound aggregate impacts on maize production and lead to greater reductions in import demand if prices are controlled or maize prices if maize prices are flexible technology adoption in high potential regions is likely to have substantially greater positive impacts on aggregate real incomes but inferior income distributional outcomes compared to technology adoption in marginal regions

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

role of agricultural research in poverty reduction lessons from the asian experience abstract the poor spend much of their income on food depend primarily on labour earnings and tend to reside in marginal agricultural areas to reduce poverty agricultural research should aim to ensure adequate food supplies by developing yield increasing technologies to increase labour demand by developing labour using technologies and to develop technologies suitable for marginal areas this article seeks to identify appropriate technologies that agricultural research should generate for poverty reduction the identification is based on a review of the experience of the green revolution in rice production in asia and an assessment of the changing structure of income sources among rural households in the philippines

why do so few hold stocks the authors investigate why 75 percent of u s households do not hold stocks despite the equity premium and predictions of expected utility models the question is relevant for privatization asset pricing and tax progressivity issues they show that risk aversion per se heterogeneity of beliefs habit persistence time nonseparability and quantity constraints on borrowing do not account for the phenomenon a wedge between borrowing and lending rates and minimum investment requirements are plausible but empirically weak factors more promising explanations are inertia and departures from expected utility maximization there is also qualified support for nondiversifiable income risk as a contributing factor copyright 1995 by royal economic society

technology production environment and household income assessing the regional impacts of technological change abstract this paper clarifies the factors determining the welfare effects of improved agricultural technologies when technology diffusion is unevenly distributed across production environments household level income effects are shown to depend primarily on a whether the economy is open or closed with respect to world markets b whether households are net consumers or net producers of the commodity for which technological change occurs c whether households are adopters or non adopters of the new technology d the degree to which labor is mobile across agricultural regions and e government intervention in commodity and or factor markets a review of recent empirical work indicates considerable variation in the relative strength of these various factors across countries and that assumptions regarding the mechanism by which commodity prices are determined endogenously as in a closed economy or exogenously as in an open economy is especially critical

optimal monetary policy distribution efficiency versus production efficiency this paper investigates the trade off between distribution effect and production effect of monetary policy when there exist unobservable idiosyncratic liquidity shocks in the absence of risk sharing arrangements such as a credit market monetary policy serves to provide ex post insurance to smooth consumption specifically issuing interest bearing bonds restores credit transactions on money through bond money exchanges such a policy has a positive distribution effect but the resulting inflation hampers production efficiency it is demonstrated that the trade off between distribution efficiency gain and production efficiency loss would result in net welfare enhancement if consumers are relative risk averse enough politique monetaire optimale efficacite dans la distribution versus efficacite dans la production ce memoire examine la relation d equivalence entre l effet sur la distribution et l effet sur la production de la politique monetaire quand existent des chocs de liquidite idiosyncratiques non observables en l absence d arrangement pour le partage des risques tel qu un marche du credit la politique monetaire sert d assurance ex post pour lisser les variations dans les niveaux de consommation specifiquement emettre des obligations qui paient des interets restore les transactions monetaires de credit via les echanges obligations monnaie une telle politique a un effet positif sur la distribution mais l inflation qui en resulte nuit a l efficacite de la production on montre que la relation d equivalence entre les gains d efficacite dans la distribution et la perte d efficacite dans la production resultent en une amelioration du niveau net de bien etre si les consommateurs ont une aversion suffisamment grande au risque relatif

how important is discount rate heterogeneity for wealth inequality abstract this paper investigates the role of discount rate heterogeneity for wealth inequality the key idea is to infer the distribution of preference parameters from the observed age profile of wealth inequality the contribution of preference heterogeneity to wealth inequality can then be measured using a quantitative life cycle model i find that discount rate heterogeneity increases the gini coefficient of wealth by around 0 07 to levels that are close to the data the share of wealth held by the richest 1 of households rises by around 0 04 but falls short of the data by more than 10 percentage points discount rate heterogeneity also helps to account for the large wealth inequality observed among households with similar lifetime earnings

the impact of investment behaviour for individual welfare the industrialized world has experienced a demographic shift that is straining public pension systems employer sponsored pension plans change from defined benefit to defined contribution more emphasis is put on individually managed retirement funds one concern with this movement is the potential negative effect on individual welfare if households investment behaviour is suboptimal using micro level us data we compare the optimal utility computed using a lifecycle model with the actual utility as reflected in empirical asset allocation choices average estimated welfare costs are below 3 of households endowment assets and human capital yet specific population groups experience higher welfare costs

intergenerational transfers and the accumulation of wealth h t ouseholds acquire wealth from two sources they save out of income they have earned and they receive transfers from other people the first method of wealth accumulation goes under the name of life cycle saving in which people save during their working lives and dissave after retirement the second involves either an inter vivos transfer that is a transfer between living people or a bequest a transfer that occurs at the death of the donor while inter vivos transfers and bequests will arise in dynastic models where preferences include a taste for the well being of one s descendents few empirical life cycle models reflect these concerns indeed a sharp debate has arisen over the ability of the simple life cycle model to explain observed wealth accumulation understanding the relative sizes of these sources of wealth accumulation affects a variety of issues for example the effects of government debt social insurance public transfer programs estate taxes and incentives for charitable giving depend to some extent on the magnitude and nature of private saving and transfers of wealth analyses of the inequality of wealth may depend on whether most of wealth is earned or received as transfers appropriate policies for encouraging private saving may look rather different depending on whether most saving is to be consumed later in life or passed along to the next generation finally evidence on transfer patterns relates to more fundamental

reasonable expectations on the prospects for documenting the impact of agricultural research on poverty in ex post case studies abstract the increasing emphasis on poverty alleviation as a motivation for investing in public sector international agricultural research is discussed from the perspective of practitioners engaged in ex post impact evaluation context is largely provided from the experience of the international potato center cip in impact assessment of improved potato and sweet potato technologies the poverty content of 10 cip related success stories of technological change was qualitatively assessed with a checklist of key questions with this admittedly crude method the size of project net present value npv appears to be an informative guide to the magnitude of poverty effects hence projects that generate widespread benefits to many people particularly to net consumers of food crops remain likely to be the most effective vehicles to contribute to poverty alleviation from public sector investments in the improvement of food crops in developing countries