modeling skewness with the linear stochastic plateau model to determine optimal nitrogen rates accurate modeling of skewness is needed to increase the actuarial fairness of crop insurance we test day s conjecture that crop yield skewness becomes negative as nitrogen rates increase and determine how well a linear response stochastic plateau lrsp production function matches the pattern of observed skewness using four long term nitrogen experiments stillwater wheat is consistent with day s conjecture but the skewness for lahoma and altus wheat yields as well as altus cotton yields are not the lrsp assumes normal random effects and can explain only a small part of observed skewness so a new lrsp with skew normal random effects is introduced which comes closer to explaining the observed skewness and should increase the accuracy of nitrogen rate recommendations negative skewness reduced optimal nitrogen rates and positive skewness increased optimal nitrogen rates

technology adoption under production uncertainty theory and application to irrigation technology we propose a theoretical framework to analyze the conditions under which a farmer facing production uncertainty due to a possible water shortage and incomplete information will adopt a more efficient irrigation technology a reduced form of this model is empirically estimated using a sample of 265 farms located in crete greece the empirical results suggest that farmers choose to adopt the new technology in order to hedge against production risk in addition we show that the farmer s human capital also plays a significant role in the decision to adopt modern more efficient irrigation equipment

safety first criteria and their measures of risk a cardinal measure of risk which represents the safety first criteria is defined the functional form of that measure is determined for a subgroup of risk averse agents that do not have money illusion an empirical illustration of possible applications of that measure shows a method of identifying the subgroup of agents for which a given alternative dominates the others in a group of risky alternatives when none of these alternatives dominates any of the others according to the first and the second criteria of stochastic dominance

optimal self protection in two periods on the role of endogenous saving self protection is a costly investment to reduce the probability of loss this paper studies optimal self protection in a two period model with endogenous saving in a setting with a binary loss we show that prudence is negatively associated with the optimal level of self protection consistent with results obtained in single period models we provide intuition for this finding with the help of a recent approach based on stochastic dominance furthermore we determine the effect of interest rate risk on optimal self protection and study a model in which a decision maker engages in advance effort to increase the probability of facing a better risky situation all our results suggest that the understanding of advance self protection crucially hinges on whether the decision maker also uses saving to optimize intertemporal consumption utility if so the fact that self protection expenditures are upfront turns out to be irrelevant

modeling conditional yield densities given the increasing interest in agricultural risk many have sought improved methods to characterize conditional crop yield densities while most have postulated the beta as a flexible alternative to the normal others have chosen nonparametric methods unfortunately yield data tends not to be sufficiently abundant to invalidate many reasonable parametric models this is problematic because conclusions from economic analyses which require estimated conditional yield densities tend not to be invariant to the modeling assumption we propose a semiparametric estimator that because of its theoretical properties and our simulation results enables one to empirically proceed with a higher degree of confidence copyright 2003 oxford university press

poverty in canada and the united states measurement trends and implications although canada and the united states are two of the richest countries in the world many canadians and americans perceive themselves and are perceived by others to be poor which raises the issue of how best to measure poverty within canada there are widespread worries that the self image of canada as a place with relatively little poverty somewhat kinder and gentler than the united states may be a bit outdated see graves dugas and beauchamp 1999 angus reid 1999 poverty in canada has been rising while in the united states it has been falling in recent years which raises the issues of why that has been happening and what it will mean in the longer term for canada and the united states as a whole in this paper therefore i begin by asking how poverty in affluent countries should be measured before examining recent evidence on poverty intensity and its social significance in section 1 the use of the sen shorrocks thon index of poverty intensity is advocated and the poverty box is introduced as a summary graphical representation in section 2 recent data are presented on poverty in europe and north america and it is noted that between 1994 and 1997 canadian provinces became quite similar to many u s states in poverty intensity a fixed effects model is used in section 3 to examine whether changes in trade exposure the unemployment rate unemployment insurance and social assistance are significant determi

risk and precautionary saving in two person households the existing literature on precautionary saving is based almost entirely on the assumption that the household acts as if it consisted of a single individual decision taker in reality saving decisions are typically taken by two person households this paper examines the implications of this observation for the existence of precautionary saving and shows that the assumption that the individual utility functions satisfy the conditions for precautionary saving to exist can imply that the household exhibits precautionary saving but only under strong assumptions on the type of risk change being considered

testing for poverty dominance an application to canada the paper proposes and applies statistical tests for poverty dominance that check for whether poverty comparisons can be made robustly over ranges of poverty lines and classes of poverty indices this helps provide both normative and statistical confidence in establishing poverty rankings across distributions the tests which can take into account the complex sampling procedures that are typically used by statistical agencies to generate household level surveys are implemented using the canadian survey of labour and income dynamics slid for 1996 1999 and 2002 although the yearly cumulative distribution functions cross at the lower tails of the distributions the more recent years tend to dominate earlier years for a relatively wide range of poverty lines failing to take into account slid s sampling variability as is sometimes done can inflate significantly one s confidence in ranking poverty taking into account slid s complex sampling design as has not been done before can also decrease substantially the range of poverty lines over which a poverty ranking can be inferred

testing the stochastic structure of production a flexible moment based approach conventional production function specifications are shown to impose restrictions on the probability distribution of output that cannot be tested with the conventional models these restrictions have important implications for firm behavior under uncertainty a flexible representation of a firm s stochastic technology is developed based on the moments of the probability distribution of output these moments are a unique representation of the technology and are functions of inputs large sample estimators are developed for a linear moment model that is sufficiently flexible to test the restrictions implied by conventional production function specifications the flexible moment based approach is applied to milk production data the first three moments of output are statistically significant functions of inputs the cross moment restrictions implied by conventional models are rejected

source country earnings and emigration while higher wages at home reduce the incentive to emigrate by increasing the opportunity cost of working abroad they also facilitate emigration for liquidity constrained individuals our theoretical model examines the interaction between these two effects we show that i the relationship between the home country wage and emigration pressure is hump shaped ii the hump is more pronounced the lower the cost of migration and iii the ratio of high to low skilled emigrants is decreasing in the home country wage we test our model empirically for three different skill groups of emigrants and find strong evidence in support of the three hypotheses the peak emigration rate for the low skilled is estimated at 4000 at 2000 ppp adjusted prices a rise in the annual per capita income of the source country from 231 of the poorest economy in our sample to 4000 is associated with an increase in the emigration rate of its low skilled workers from about 2 7 to 5 0

ethically flexible measures of poverty this paper introduces new measures of both relative and absolute poverty using the notion of representative income of a community corresponding to the censored income distribution these new measures satisfy the monotonicity and transfer axioms proposed by sen 1976 in all cases

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

estimating yield gaps with limited data an application to united states wheat the objective of this research is to estimate and analyze the gap between in trial yield potential on farm yield potential and actual on farm wheat yields yield gaps are quantified by measuring how varietal mean yields have changed over time due to productivity increases generated by public and private wheat breeding programs variety performance trial data for kansas winter wheat are used to summarize the evolution of wheat yields over the time period 1985 to 2011 a measure of yield potential is compared to actual on farm yields to derive implications for wheat industry stakeholders persistent and expanding yield gaps between potential yield and actual on farm yield are measured and analyzed producers variety adoption decisions explain a relatively small portion of this gap and producers have become more effective at identifying and adopting yield enhancing varieties over time the largest portion of these gaps was explained by on farm production decisions

disappointment in decision making under uncertainty decision analysis requires that two equally desirable consequences should have the same utility and vice versa most analyses of financial decision making presume that two consequences with the same dollar outcome will be equally preferred however winning the top prize of 10 000 in a lottery may leave one much happier than receiving 10 000 as the lowest prize in a lottery this paper explores the implications of disappointment a psychological reaction caused by comparing the actual outcome of a lottery to one s prior expectations for decision making under uncertainty explicit recognition that decision makers may be paying a premium to avoid potential disappointment provides an interpretation for some known behavioral paradoxes and suggests that decision makers may be sensitive to the manner in which a lottery is resolved the concept of disappointment is integrated into utility theory in a prescriptive model

crop yield skewness under law of the minimum technology no satisfactory motivation has been forwarded in favor of any crop yield distribution including the normal this article explores the foundations of yield distributions for the law of the minimum resource constraint technology at the plot level of analysis with independent identical uniform resource availability distributions the yield skew is positive whereas it is negative whenever the distributions are normal simulations show how asymmetries in resource availabilities determine skewness it is suggested that a negative yield skew occurs whenever production is tightly controlled so that the left tails of some resources availabilities distributions are thin irrigation may increase yield skewness copyright 2009 oxford university press

are crop yields normally distributed the evidence for nonnormality of crop yields is reassessed three methodological problems are identified in typical yield distribution analyses i misspecification of the nonrandom components of yield distributions ii missreporting of statistical significance and iii use of aggregate timeseries ats data to represent farm level yield distributions one or more of these problems infect virtually all evidence against normality to date the positive contribution of the article is a set of principles that must be followed in any valid investigation of yield normality

on shorrocks reinvestigation of the sen poverty index this paper demonstrates that the shorrocks econometrica 63 225 1230 1995 modification of the sen econometrica 44 219 231 1976 poverty index drops out as a particular case of the chakravarty canadian journal of economics 16 74 85 1983 general ethical index of poverty

poverty and inequality under income and price dispersions many policies simultaneously affect the distribution of prices and incomes in the economy moreover a bias may occur when there is a stochastic relationship between prices and incomes and this relationship is being ignored it is therefore important to dispose of an analytical framework for welfare analysis that could account for changes in this joint distribution how can the joint influences of price and income distributions on poverty and inequality indicators be analysed we offer a method to deal with this problem by using parametric formulae of poverty and inequality measures we propose statistical indicators for the levels variabilities and a statistical link of price indices and nominal living standards these indicators are consistent with an approximation of the problem based on a bivariate lognormal distribution of price indices and nominal living standards our analysis provides hints about the social welfare impact of economic shocks or policies affecting levels variabilities and correlation of prices and incomes intuitive insights are obtained while using arithmetic means and variances instead does not lead to illuminating results the role of price and income variabilities for poverty and inequality is more complex than generally expected with the possibility of several variation regimes empirical investigation of these statistics would guide social policies

revisiting the sen poverty index a modification of the official sen poverty index yields an index which is not only continous in individual incomes and consistent with the transfer axiom but also admits a geometric interpretation in terms of the area beneath a graph called the inverse generalized lorenz curve for normalized poverty gaps by jenkins and lambert 1993 or the poverty gap profile by shorrocks 1994

international comparisons of poverty intensity index decomposition and bootstrap inference this paper proposes an alternative formulation for the sen shorrocks thon sst index of poverty intensity that is appropriate for survey data with sampling weights it also decomposes the sst index into the poverty rate the average poverty gap ratio among the poor and the overall gini index of poverty gap ratios to account for sampling variation in estimates of poverty intensity this paper uses the bootstrap method to compute confidence intervals and presents international comparisons using luxembourg income study lis data from the 1970s to the 1990s cross sectional and longitudinal analyses indicate that the percentage change in poverty intensity can be approximated by the sum of percentage changes in the poverty rate and average poverty gap ratio since changes in the overall gini index of poverty gap ratios are negligible in the early 1970s poverty intensity in canada and the united states was almost indistinguishable but in the 1970s canadian poverty intensity decreased large increases in poverty intensity occurred in the 1980s in the united states the united kingdom and sweden

multilateral resistance to migration the rate of migration observed between two countries does not depend solely on their relative attractiveness but also on the one of alternative destinations following the trade literature we term the influence exerted by other destinations on bilateral flows as multilateral resistance to migration and we show how it can be accounted for when estimating the determinants of migration rates in the context of a general individual random utility maximization model we propose the use of the common correlated effects estimator pesaran 2006 and apply it to high frequency data on the spanish immigration boom between 1997 and 2009 compared to more restrictive estimation strategies developed in the literature the bias goes in the expected direction we find a smaller effect of gdp per capita and a larger effect of migration policies on bilateral rates

tailored to the extremes quantile regression for index based insurance contract design a new approach for weather index based insurance design based on quantile regression qr to condition the yield index dependency is developed and compared to standard regression technique three conceptual different risk measures i e expected utility expected shortfall and a spectral risk measure are used to evaluate the risk reducing properties of these contracts our findings show that qr is much more powerful in establishing the yield index dependency and lead for all risk measures to a higher risk reduction than the standard technique ordinary least squares ols thus qr leads to a more efficient contract design which is beneficial for both the insurer smaller remaining risk and the insured higher demand and willingness to pay our empirical application is based on a 31 years long time series of wheat yield data from northern kazakhstan

rational inattention and migration decisions abstract acquiring information about destinations can be costly for migrants we model information frictions in the rational inattention framework and obtain a closed form expression for a migration gravity equation that we bring to the data the model predicts that flows from countries with a higher cost of information or stronger priors are less responsive to variations in economic conditions in the various destinations as migrants rationally get less information before deciding where to move the econometric analysis reveals systematic heterogeneity in the pro cyclical behavior of migration flows across origins that is consistent with the existence of information frictions

geography of crop yield skewness analysis of crop yield distributions provides insights into better understanding how natural resources shape agricultural productivity this study seeks to provide a rigorous theoretical and empirical understanding of the effects of exogenous geographic and climatic factors on the first three moments of crop yields with focus on the third moment we hypothesize that exogenous factors having beneficial effects on crop production should make crop yield distributions less positively or more negatively skewed we employ a large crop insurance data set for corn soybean and wheat to find general support for our natural resources determines skewness hypothesis the proposed statistical method optimally uses correlations between the first three moments it significantly improves estimation performance over existing methods including the linear moment model which has been commonly applied in the literature

the welfare effects of crop biodiversity as an adaptation to climate shocks in kenya abstract this paper investigates the effects of crop biodiversity on farm income and production risk using a large panel dataset of rural households in kenya we consider three different metrics of in situ on farm crop diversification richness evenness and concentration we apply a partial moments based model to test the effects of each strategy on welfare defined as expected crop income variability variance and downside risk skewness our comprehensive econometric approach differentiates climatic shocks weather and climate change the results suggest that the benefits from greater diversification in terms of enhanced land productivity and lower production costs could surpass the foregone benefit from greater efficiency associated with more concentrated production systems crop richness and evenness each reduce exposure to crop income risk especially for more vulnerable farmers who produce below the expected revenue threshold farmers who rely on greater crop specialization on the contrary are more exposed to crop income risk

asymmetry partial moments and production risk partial moment functions are proposed as a flexible way to characterize and estimate asymmetric effects of inputs on output distributions methods for econometric estimation of partial moment functions and tests for input symmetry and location scale distributions are presented a monte carlo study demonstrates properties of proposed tests a study of ecuadorian potato production illustrates the methods hypotheses of input symmetry and location scale are rejected a risk value model based on partial moments implies that fertilizer is risk increasing and fungicides and labor are risk reducing in potato production whereas an expected utility model based on full moments has the opposite implications

testing day s conjecture that more nitrogen decreases crop yield skewness whilecontroversysurroundsskewnessattributesoftypicalyielddistributions abetterunderstandingis importantforagriculturalpolicyassessmentandforcrop insuranceratesetting day 1965 conjectured that crop yield skewness declines with an increase in nitrogen use at low levels but not at higher levels employing four corn yield experimental plot datasets we investigate the conjecture by introducing a a flexible bayesian extension of the just pope technology to incorporate skewness and b a quantilebased measure of skewness shift bayesian estimation provides strong evidence in favor of negative skewnessatcommercialnitrogenratesandforday sconjecture therewasweakerevidenceinfavorof positively skewed cotton yield and little evidence in favor of the conjecture the results are confirmed by the quantile based measure we also find evidence that skewness becomes more negative upon moving from corn after corn to corn after soybean

heteroscedasticity or production risk a synthetic view two veins of literature namely production risk literature and stochastic frontier analysis are examined both fields are concerned of output variation the former due to exogenous shocks the latter due inefficiency by covering the literature from both the fields this review suggests that the concept of heteroscedasticity can be utilized to build a synthesis between these mainly separate branches of literature however the synthetic approach brings a challenge how to differentiate between different sources of output variation this challenge is identified as the main obstacle to meaningfully combine the two approaches

more than mean effects modeling the effect of climate on the higher order moments of crop yields this article proposes the use of moment functions and maximum entropy techniques as a flexible approach for estimating conditional crop yield distributions we present a moment based model that extends previous approaches and is easily estimated using standard econometric estimators predicted moments under alternative regimes are used as constraints in a maximum entropy framework to analyze the distributional impacts of switching regimes an empirical application for arkansas mississippi and texas upland cotton demonstrates how climate and irrigation affect the shape of the yield distribution and allows us to illustrate several advantages of our moment based maximum entropy approach

network effects and the dynamics of migration and inequality theory and evidence from mexico international migration is costly and initially only the middle class of the wealth distribution may have both the means and incentives to migrate which can increase inequality in the sending community however the migration networks formed lower the costs for future migrants which can in turn lower inequality this paper shows both theoretically and empirically that wealth has a nonlinear effect on migration and then examines the empirical evidence for an inverse u shaped relationship between emigration and inequality in rural sending communities in mexico after instrumenting we find that the overall impact of migration is to reduce inequality across communities with relatively high levels of past migration we also find some suggestive evidence for an inverse u shaped relationship among communities with a wider range of migration experiences

econometric estimation of producers risk attitudes general methods are proposed for the identification and econometric estimation of the parameters of the distribution of risk attitudes in a producer population the proposed methods also provide the basis for the development of statistical tests of model specification and of behavioral hypotheses econometric risk attitude estimation is shown to be possible under less restrictive conditions than previously believed a moment based version of the general model is applied to indian data and the econometrically estimated risk attitudes are presented and compared to experimental results for a similar group of producers

how borrowing constraints hinder migration theoretical insights from a random utility maximization model we provide a theoretical framework to analyze how financial constraints hinder migration introducing wealth heterogeneity and borrowing constraints into a random utility maximization model of migration we find evidence of multilateral resistance to migration stemming from borrowing constraints we calibrate the model on 22 european countries and we show that omitting the constraints biases upward the estimation of bilateral migration rates we then simulate an increase in the bilateral cost of migration to the united kingdom we find that omitting the constraints biases downward the change entailed by the cost increase in the bilateral rates of migration to all destinations

catastrophic medical expenditure risk we propose a measure of household exposure to particularly onerous medical expenses the measure can be decomposed into the probability that medical expenditure exceeds a threshold the loss due to predictably low consumption of other goods if it does and the further loss arising from the volatility of medical expenses above the threshold depending on the choice of threshold the measure is consistent with a model of reference dependent utility with loss aversion unlike the risk premium the measure is only sensitive to particularly high expenses and can identify households that expect to incur such expenses and would benefit from subsidised but not actuarially fair insurance an empirical illustration using data from seven asian countries demonstrates the importance of taking account of informal insurance and reveals clear differences in catastrophic medical expenditure risk across and within countries in general risk is higher among poorer rural and chronically ill populations

on the watts multidimensional poverty index and its decomposition summary the multidimensional extension of the watts poverty index may be expressed as a function of five determinants measuring respectively the impacts of what are defined in the paper as the watts poverty gap ratio the theil bourguignon index of inequality among the poor the overall headcount ratio the weights of the various dimensions and some measure of correlation between the various dimensions using the shapley decomposition we apply this index to world data on the per capita gdp life expectancy and literacy rates and derive the contributions of the five determinants defined above to the variation of this index during 1993 2002

a practitioners guide to gravity models of international migration the use of bilateral data for the analysis of international migration is at the same time a blessing and a curse it is a blessing because the dyadic dimension of the data allows researchers to address a number of previously unanswered questions but it is also a curse for the various analytical challenges it gives rise to this paper presents the theoretical foundations of the estimation of gravity models of international migration and the main difficulties that have to be tackled in the econometric analysis such as the nature of migration data how to account for multilateral resistance to migration or endogeneity we also review some empirical evidence that has considered these issues

warming temperatures will likely induce higher premium rates and government outlays for the u s crop insurance program likely climate change impacts include damages to agricultural production resulting from increased exposure to extreme heat considerable uncertainty remains regarding impacts on crop insurance programs we utilize a panel of u s corn yield data to predict the effect of warming temperatures on the mean and variance of yields as well as crop insurance premium rates and producer subsidies while we focus on corn we demonstrate that the subsidy impacts are likely to carry over to other major program crops we find that warming decreases mean yields and increases yield risk on average which results in higher premium rates under a 1 c warming scenario we find that premium rates at the 90 coverage level will increase by 39 on average however there is considerable statistical uncertainty around this average as the 95 confidence interval spans from 22 to 61 we also find evidence of extensive cross sectional differences as the county level rate impacts range from a 10 reduction to a 63 increase results indicate that exposure to extreme heat and changes in the coefficient of variation are large drivers of the impacts under the 1 c warming scenario we find that annual subsidy payments for the crop insurance program could increase by as much as 1 5 billion representing a 22 increase relative to current levels this estimate increases to 3 7 billion 57 under a 2 c warming scenario our results correspond to a very specific counterfactual the marginal effect of warming temperatures under current technology production and crop insurance enrollments these impacts are shown to be smaller than the forecasted impacts under a commonly used end of century general circulation model for even the most optimistic co emissions projection

third degree stochastic dominance here f x and g x are less than cumulative probability distributionis where x is a continuous or discrete random variable representing the outcome of a prospect the closed interval a b is the sample space of both prospects the integral shown in rule 2 and those shown throughout the paper are stieltjes integrals recall that the stieltjes integral fb f x dg x exists if one of the functions f and g is continuous and the other has finite variation in a b let d1 d2 and d3 be three sets of utility functions x d1 is the set containing all utility functions with 4 x and 1 x continuous and 41 x 0 for all xe a b d2 is the set with x 1 x 2 x continuous and q j x 0 02 x o for all xc a b d3 is the set with x 1 x 2 x 3 x continuous and 1 x 04 2 x o o for all xc a b here 1 x denotes the ith derivative of x hadar and russell proved that rule 1 is valid for all cd1 and rutle 2 is valid for all ed2 the authors point out that the set of probability distributions that can be ordered by means of second degree stochastic dominance is in general larger than that which can be ordered by means of first degree stochastic dominance note that in rule 2 they assume that x is not only an increasing function of x but also exhibits weak global risk aversion a condition guaranteed by requiring the second derivative of x to be nonpositive in this paper a condition which will be called third degree stochastic dominance is considered it is based on the following assumption about the form of the utility function x from a normative point of view one expects the risk premium associated with an uncertain prospect to become smaller the greater is the individual s wealth the plausibility and implications of this assumption h ave been explored by john pratt as well as others the risk premium of an uncertain prospect is that amount by which the certainty equivalent of the prospect differs from its expected value in mathematical terms given the prospect f x with expected value a the corresponding risk premium t is obtained by solving the following equation rb

risk lovers and the rent over investment puzzle in this paper we prove existence and uniqueness of equilibrium in a rent seeking contest given a class of heterogeneous risk loving players we explore the role third order risk attitude plays in equilibrium and find that imprudence is sufficient for risk lovers to increase rent seeking investment above the risk neutral outcome moreover we show that rent can be fully dissipated in a standard tullock contest played by a large number of risk lovers

risk aversion and the propensities for self insurance and self protection for a risk averse individual the methods for reducing the expected financial impact of a loss include reducing the severity of any loss that occurs self insurance and reducing the probability of the occurrence of a loss self protection the literature on this topic has pointed to several anomalies whereby the use of self protection and self insurance yield quite unsimilar results for example ehrlich and becker 5 show that self insurance is always a substitute for market insurance an insurance company s indemnifying a loss whereas self protection and market insurance might be complements dionne and eeckhoudt 4 show that a more risk averse consumer would always invest more in self insurance activities but not necessarily more in self protection activities they argue 4 42 that this result is counterintuitive and provides an exception to the widely accepted result that increased risk aversion reduces risky activities ehrlich and becker 5 639 argue that the incentive to self protect is not so dependent on attitude towards risk both of the above papers seem to take for granted that self protection activities reduce the riskiness of the final wealth distribution however as we argue below this is not the case if riskiness is defined as in rothschild and stiglitz 14 even if we use the variance as our risk measure we do not always reduce risk via self protection dionne and eeckhoudt suggest that these results might not be robust enough to extend to models that incorporate random initial wealth risk and state dependent preferences we show that the model seems to be very robust we also explain why self protection is not at all an exception to the long standing result of arrow 1 whereby more risk averse individuals undertake a lower

joint risk preference technology estimation with a primal system applied studies of the firm in a risky environment have concentrated either on the firm s technology or on its risk preferences these models result in generally inconsistent and inefficient parameter estimates a primal model is proposed which allows a firm s preferences and technology to be estimated jointly in the presence of risk the model is applied to iowa corn production and estimated technology parameters are compared with those from other approaches modest risk aversion leads to inelastic even backbending per acre supplies and input demands yield heteroskedasticity in inputs leads to supply heteroskedasticity in prices especially for risk neutral firms

welfare approaches to the measurement of poverty a set of poverty indices is constructed which is based on an explicit view of the loss of social welfare which results from the existence of poverty in comparison t o a society in which poverty has been eliminated the indices are based on the entire distribution of income rather than only the incomes of the poor and thus embody the concept of relative deprivation formal properties of the indices are developed together with their relationship to welfare based inequality indices both are seen as subsets of a wider choice of measures dependent on a particular choice of reference distribution copyright 1987 by royal economic society

migration risk and liquidity constraints in el salvador abstract this article utilizes panel data from el salvador to investigate the use of transnational migration as an ex post risk management strategy i show that adverse agricultural conditions in el salvador increase both migration to the united states and remittances sent back to el salvador i show that in the absence of any agricultural shocks the probability that a household sent members to the united states would have decreased on average by 24 26 i also show that the 2001 earthquakes reduced net migration to the united states a one standard deviation increase in earthquake damage reduced the average probability of northward migration by 37 11 the evidence suggests that the effects of the earthquakes had more to do with households retaining labor at home to cope with the effects of the disaster than with the earthquakes disrupting migration financing

chronic and transient poverty measurement and estimation with evidence from china abstract the paper contributes to the measurement of poverty and vulnerability in three ways first it proposes a new approach to separating poverty into chronic and transient components second it provides corrections for the statistical biases introduced when using a small number of periods to estimate the importance of vulnerability and transient poverty third it applies these tools to the measurement of chronic and transient poverty in china using a rich panel data set that extends over 17 years alternative measurement techniques are found to yield significantly different estimates of the relative importance of chronic and transient poverty the precision of the estimates is also considerably enhanced by simple statistical corrections

income maximization and the selection and sorting of international migrants abstract two prominent features of international labor movements are that the more educated are more likely to emigrate positive selection and more educated migrants are more likely to settle in destination countries with high rewards to skill positive sorting using data on emigrant stocks by schooling level and source country in oecd destinations we find that a simple model of income maximization can account for both phenomena results on selection show that migrants for a source destination pair are more educated relative to non migrants the larger is the absolute skill related difference in earnings between the destination country and the source results on sorting indicate that the relative stock of more educated migrants in a destination is increasing in the absolute earnings difference between high and low skilled workers we use our framework to compare alternative specifications of international migration estimate the magnitude of migration costs by source destination pair and assess the contribution of wage differences to how migrants sort themselves across destination countries

a class of generalized sen poverty indices utilizing results from partial poverty orderings we characterize a class of generalized sen poverty indices a generalized sen poverty index is defined as the weighted area between the line of zero poverty and the censored generalized lorenz curve unlike the original sen index the generalized sen index can satisfy the key axioms for poverty measurement

on crop biodiversity risk exposure and food security in the highlands of ethiopia this paper investigates the effects of crop genetic diversity on farm productivity and production risk in the highlands of ethiopia using a moment based approach the analysis uses a stochastic production function capturing mean variance and skewness effects welfare implications of diversity are evaluated using a certainty equivalent measured as expected income minus a risk premium reflecting the cost of risk we find that the effect of diversity on skewness dominates its effect on variance meaning that diversity reduces the cost of risk the analysis also shows that the beneficial effects of diversity

measuring stochastic technology the case of tulare milk production the flexible moment based approach to production analysis is used to measure the stochastic structure of large scale dairy production in tulare county california this approach is flexible because it does not impose restrictions on the relationships between decision variables and the moments of the probability distribution of output the parameter estimates support the hypothesis that second and third moments are functions of inputs and indicate that capital intensive dairies are riskier the implied behavior of a risk averse dairy manager changed markedly when the effects of inputs on the skewness of the output distribution were included in a decision model

dynamic poverty decomposition analysis an application to the philippines summary in this paper we propose a new method of poverty decomposition our method remedies the shortcomings of existing methods and has some desirable properties such as time reversion consistency and subperiod additivity our decomposition integrates the existing methods of growth redistribution decomposition and sector based decomposition because it allows us to decompose the change in poverty into growth and redistribution components for each group e g regions or sectors in the economy our decomposition works well in cases where only partial data are available for some periods it is also flexible and can be extended to have the following six components population shift within region redistribution between region redistribution nominal growth inflation and methodological change components the empirical application of the six way decomposition to the philippines for the period 1985 2009 shows that important policies for poverty reduction may differ across regions for example the autonomous region in muslim mindanao would need growth enhancing policies whereas eastern visayas would need policies to improve the income distribution our decomposition method has a wide applicability and may complement the poverty profile approach

tax rate uncertainty factor supplies and welfare uncertainty about prospective changes in tax rates may increase factor supplies and hence the tax base permitting a reduction in tax rates that could result in a net increase in welfare under empirically relevant assumptions about attitudes towards risk we find that when an individual exclusively saves or works the tax base rises in response to greater tax rate uncertainty so that welfare could indeed increase however when an individual both saves and works the supply of the randomly taxed factor declines with increased uncertainty implying that tax revenue and welfare decrease when the nonrandom tax rate is sufficiently low

efficiency gains from liberalizing labor mobility in this paper we quantify the effect of a complete liberalization of cross border migration on the world gdp and its distribution across regions we build a general equilibrium model endogenizing bilateral migration and income disparities between and within countries our calibration strategy uses data on effective and potential migration to identify total migration costs and visa costs by education level data on potential migration reveal that the number of people in the world who have a desire to migrate is around 400 million this number is much smaller than that predicted in previous studies and reflects the existence of high incompressible migration costs in our benchmark framework liberalizing migration increases the world gdp by 11 5 12 5 percent in the medium term our robustness analysis reveals that the gains are always limited in the range of 7 0 percent with schooling externalities to 17 9 percent if network effects are accounted for

nonparametric estimation of crop insurance rates revisited with the crop insurance program becoming the cornerstone of u s agricultural policy recovering accurate rates is of paramount interest lack of yield data presents by far the most fundamental obstacle to recovery of accurate rates thisarticle employsnew methodology to estimate conditional yield densities and derive the insurance rates in our application we find the nonparametric kernel density estimator requires an additional twenty six years of yield data to estimate the shape of the conditional yield dens itiesasaccurately asthe recently developed empirical bayesnonparametric kernel density estimator such methodological improvements can significantly aid in ameliorating the data problem recovering accurate premium ratesis paramount to the actuarial soundness of the crop insurance program a program which hasgained prominence in the overall u s agricultural policy agenda the 1996 federal agricultural improvement and reform fair act signaled a new policy environment under which farmerswould be s to market forces under this policy regime crop insurance remains in some respects one of the only government subsidized income stabilizing mechanisms available to agricultural producers in addition it appears that current political forcesare in the proces sof fashioning crop insurance as the cornerstone of u s agricultural policy consider the 1999 state of the union address in which the president stated

assessing deprivation with an ordinal variable theory and application to sanitation deprivation in bangladesh the challenges associated with poverty measurement with a cardinal variable have received due attention during the last four decades but there is a dearth of literature studying how to meaningfully assess poverty with an ordinal variable this paper first proposes a class of simple intuitive and policy relevant poverty measures for ordinal variables these measures are sensitive to depth of deprivations unlike the headcount ratio moreover under appropriate restrictions the measures ensure that priority is given to the poorest among the poor while targeting monitoring and evaluating poverty alleviation programs to assess the robustness of poverty comparisons to alternative choices of parameters various stochastic dominance tests are developed some of which are themselves novel contributions to the stochastic dominance literature the empirical illustration documenting changes in sanitation deprivation in bangladesh showcases the measures ability to identify instances in which overall sanitation deprivation improved while leaving the poorest behind

issues in measuring and modeling poverty economists have relied heavily on household incomes or expenditures normalized for differences in household specific prices and demographics in their research and policy advice related to poverty and inequality recognizing the conceptual and empirical problems that confound such measures does not mean that they should be ignored instead it indicates the need for supplementary measures to capture the missing items implementing a genuinely multidimensional approach will often make the welfare rankings of social states more difficult but that fact points to the nonrobustness of low dimensional rankings this may have its own policy ramifications with the possibility of correspondence between policy instruments and welfare objectives the model types used to understand the poverty and inequity determination processes will be affected not only will there be more dependent variables to consider but variables will have potentially complex relationships these relationships will often be hard to empirically disentangle despite richer integrated and longitudinal data sets such data open rich and relevant agenda for research into the dynamics of poverty along multiple dimensions a simultaneous attack on these issues from all three fronts measurement modeling and data offers hope of establishing a credible empirical foundation for public action in fighting poverty

joint estimation of risk preferences and technology flexible utility or futility a thought experiment is designed to investigate whether the structure of risk aversion i e the changes in absolute or relative risk aversion associated with changes in wealth can be estimated with reasonable precision from agricultural production data findings strongly suggest that typical production data are unlikely to allow identification of the structure of risk aversion a flexible utility parameterization is found to slightly worsen technology parameter estimates results also indicate that even under a restricted utility specification utility parameter estimates are biased further their quality is much worse when shocks are not large or samples are small

discontinuous losses from poverty generalized pα measures and optimal transfers to the poor abstract this paper examines the distributional properties of poverty measures which are discontinuous at the poverty line it is shown that among all the additive poverty measures only those measures with some discontinuous jump at the poverty line are such that it is optimal to allocate a given antipoverty budget either to the richest of the poor or to the poorest of the poor or to both a special class of such poverty measures is an extension of the well known p the properties of which are investigated

poverty dominant program reforms the role of targeting and allocation rules we propose simple graphical methods to identify poverty reducing marginal reforms of transfer programs the methods are based on program dominance curves that display cumulative program benefits weighted by powers of poverty gaps these curves can be decomposed simply as sums of targeting dominance curves and allocation dominance ones and can serve to verify whether the assessment of marginal program reforms is sensitive to the choice of poverty lines and poverty measures as well as to differences across programs in revenue sources and incentive effects

equity regarding poverty measures differences in needs and the role of equivalence scales the paper investigates the definition of equity regarding poverty measures when there are different household types in the population it demonstrates the implications of a between type regressive transfer principle for poverty measures for the choice of poverty lines and for the measurement of living standard the role of equivalence scales which are popular in empirical work on poverty measurement is clarified ce memoire examine la definition de mesures de pauvrete fondees sur l equite quand existent differents types de menages dans la population on montre les implications d un principe de transfert regressif entre types de menages pour les mesures de pauvrete pour la definition des seuils de pauvrete et pour la mesure du niveau de vie on clarifie le role des echelles d equivalence qui sont d un usage generalise dans les travaux sur la mesure de la pauvrete

a re count of poverty in us central cities just who and where are the urban poor poverty remains a persistent problem in central cities across the us and the government s approach to measuring it is not without shortcomings this paper applies recently developed innovations in poverty measurement and presents improved estimates of central city poverty across time a broader and more comprehensive income concept is employed to measure family resources and important distributional aspects of poverty are incorporated by using the sen index in general sen indexes for the central city are significantly reduced when comprehensive income is used to evaluate poverty motivating these changes are the substantial reductions that occur in the depth of poverty and the relative income inequality among poor central city residents regionally the results suggest that the elements of comprehensive income have their greatest impact on estimates of poverty in southern central cities while the central cities of the west are least affected

stochastic technology risk preferences and adoption of site specific technologies a model of farmer decision making is developed to determine the extent to which uncertainties about soil fertility and weather affect the value of site specific technologies ssts using jointly estimated risk and technology parameters uncertainty can lead risk averse farmers to apply more fertilizers and generate more pollution than in the certainty case ignoring uncertainty and risk aversion would overestimate the economic and environmental benefits of ssts and underestimate the subsidy required to induce adoption accounting for uncertainties and risk preferences might explain the low observed adoption rates of ssts improving the accuracy of ssts would increase the incentives for adoption

do risk lovers invest in self protection we show that there is a class of risk lovers who optimally choose a positive level of self protection investment in most cases a risk lover increases his self protection investment as he becomes less downside risk averse

subjective economic welfare beyond growth it is common that economists are used to establish a direct relationship between growth and welfare nevertheless the link among these variables not always is so virtuous this suspicion went in the last years to investigating about the perception of people on your proper welfare the slogan was to know if the positive variations in the growth the revenue or the employment generate earnings of welfare it is necessary to consult the individuals the subjective studies of welfare increased substantially since then confirming the suspicions improvements in the objective indicators of welfare not always are perceived as such by the individuals the intention of this work will be to develop an index of economic welfare that allows measure the welfare perceived by the population the results obtained in the argentine economy between 2005 and 2008 will be presented and his results will be compared with the evolution of the objective indicators

aggregate poverty measures the way poverty is measured is important for an understanding of what has happened to poverty as well as for anti poverty policy evaluation sen s 1976 pathfinding work has motivated many researchers to focus on the way poverty should be measured a poverty measure argued by sen should satisfy certain properties or axioms and the desirability of a poverty measure should be evaluated by these axioms during the last two decades many researchers have adopted the axiomatic approach pioneered by sen to propose additional axioms and develop alternative poverty measures the objective of this survey is to provide a clarification on the extensive literature of aggregate poverty measures in this survey we first examine the desirability of each axiom the properties of each poverty measure and the interrelationships among axioms the desirability of an axiom cannot be evaluated in isolation and some combination of axioms may make it impossible to devise a satisfactory poverty measure some axioms can be implied by other axioms combined and so are not independent some others are ad hoc and are disqualified as axioms for poverty measurement based on the interactions among axioms we identify the core axioms which together have a strong implication on the functional form of a poverty measure we then review poverty measures that have appeared in the literature evaluating the interrelationships among different measures and examining the properties of each measure the axioms each measure satisfies violates are also summarized in a tabular form several good poverty measures which have not been documented by previous surveys are also included

pesticide use environmental spillovers and efficiency a dea risk adjusted efficiency approach applied to dutch arable farming pesticides are widely used by crop producers in developed countries to combat risk associated with pests and diseases however their indiscriminate use can lead to various environmental spillovers that may alter the agricultural production environment thus contributing to production risk this study utilises a data envelopment analysis dea approach to measure performance of arable farms incorporating pesticides environmental spillovers and output variance as undesirable outputs in the efficiency analysis and taking explicitly into account the effect of pesticides and other inputs on production risk the application focuses on panel data from dutch arable farms over the period 2003 2007 a moment approach is used to compute output variance providing empirical representations of the risk increasing or decreasing nature of the used inputs finally shadow values of risk adjusted inputs are computed we find that pesticides are overused in dutch arable farming and there is a considerable evidence of the need for decreasing pesticides environmental spillovers

equity and policy effectiveness with imperfect targeting abstract we propose a general approach that jointly integrates horizontal and vertical equity criteria in the assessment of poverty alleviation programs with the strength of each criterion being captured through its own inequity aversion parameter this contrasts with the assessment of poverty alleviation programs done with simple under coverage and leakage ratios or with other methods that do not take into account the heterogeneity of the poor and that do not address directly the social benefits of achieving normative criteria our methodology is illustrated using tunisian data and two alternative poverty alleviation policies we find inter alia that the social ranking of commodity and socio demographic targeting in tunisia depends on the policymaker s comparative preference for vertical and horizontal equity

stochastic dominance analysis without the independence axiom we characterize the consistency of a large class of nonexpected utility preferences including mean variance preferences and prospect theory preferences with stochastic orders for example stochastic dominances of different degrees our characterization rests on a novel decision theoretic result that provides a behavioral interpretation of the set of all derivatives of the functional representing the decision maker s preferences as an illustration we consider in some detail prospect theory and choice acclimating preferences two popular models of reference dependence under risk and we show the incompatibility of loss aversion with prudence this paper was accepted by james smith decision analysis

gender and multidimensional poverty in nicaragua an individual based approach most existing empirical papers concerned about multidimensional poverty use the household as the unit of analysis so that the multidimensional poverty status of the household is equated with the multidimensional poverty status of all its members this assumption ignores intra household inequalities additionally households containing both a female and a male cannot contribute to a gender gap in poverty so gender differentials in poverty cannot be estimated but the sustainable development goals have put special emphasis on gender equality therefore new measures able to capture the gender differences are needed consequently in this paper we propose an individual based multidimensional poverty measure in order to estimate the three i s of multidimensional poverty incidence intensity and inequality in nicaragua as well as the gender differentials we also estimate logit regressions to better understanding the determinants of multidimensional poverty in this country overall we find that there are statistically significant gender differences in multidimensional poverty in nicaragua but they are estimated to be small and lower than 5 however the gender differential in inequality is larger than 10 and it suggests that multi dimensionally poor women are living in very intense poverty when compared with multi dimensionally poor men we also find that the elderly and children are the most vulnerable people in terms of multidimensional poverty in this country furthermore when information on employment domestic work and social protection is considered in the analysis the gender gaps become more substantial and women are more likely to be poor than men

the story of the moment risk averse cypriot farmers respond to drought management this article illustrates the importance of estimating risk preferences when evaluating water policy using agricultural production data from the kiti region of cyprus we estimate farmers risk preferences a la antle journal of business and economic statistics 1 192 201 1983 american journal of agricultural economics 69 509 22 1987 and show sensitivity to higher order moments of profit such as skewness we show that farmers in the kiti region are risk averse with risk premiums in the region of 20 of expected profit we use these estimates to analyse the impact of a water quota from the perspective of three policy makers who differ only in their understanding of farmers risk preferences we show in the case of kiti that policy makers who model risk preferences incorrectly that is either a assume risk neutrality or b ignore down side risk wrongly predict the magnitude and direction of input responses and therefore the magnitude of welfare changes this highlights the importance of accomm

out migration wealth constraints and the quality of local amenities the relation between income and migration intentions can be monotonically decreasing increasing or inverse u shaped dependent on the level of migration cost relative to wealth and if individuals are credit constrained using unique individual level data covering countries in three geographic regions sub saharan africa asia and latin america we show that migration intentions respond to individual wealth and that the pattern differs across the country groups studied in a manner compatible with the predictions of our simple model we also show that contentment with various dimensions of local amenities such as public services and security are key determinants of migration intentions

minimum distribution sensitivity poverty aversion and poverty orderings abstract this paper introduces a measure of distribution sensitivity which is similar to arrow pratt s measure of risk aversion for a poverty index the measure also gauges poverty aversion and has a clear and straightforward interpretation using this measure we can define various classes of minimum distribution sensitive poverty indices we show that the ordering condition for such a class of poverty indices is simply a generalized poverty deprivation profile dominance properties and implications of this dominance condition are analyzed and poverty orderings by different classes of poverty measures are compared journal of economic literature classification number i32