modeling farm level crop insurance demand with panel data a random effects binomial probit model is applied to data for a panel of kansas wheat farms to examine multiple peril crop insurance demand a theoretical model is developed which suggests inclusion of the moments of both market return and the return to insurance empirical results indicate that the first and second moments of both market return and the returns to insurance are significant the price elasticity of demand is estimated to be 0 65 preseason weather variables when included in the models were not found to be significant failing to support the hypothesis of intertemporal adverse selection

the poverty gap in school spending following the introduction of title i abstract title i of the 1965 elementary and secondary education act explicitly directed more federal aid for k 12 education to poorer areas for the first time in us history with a goal of promoting regional convergence in school spending using newly collected data we find some evidence that title i narrowed the gap in per pupil school spending between richer and poorer states in the short to medium run however the program was small relative to then existing poverty gaps in school spending even in the absence of crowd out by local or state governments the program could have reduced the gap by only 15 percent

designing and rating an area yield crop insurance contract this article documents the design and rate making procedures used in the development of the group risk plan grp the new federal crop insurance product that insures based on area yield the authors of this article worked closely with personnel in the federal crop insurance corporation and others in developing methodological and practical constraints needed in implementing a workable area yield contract grp indemnity payments are made based on percentage shortfalls in actual county yields relative to a forecasted yield historical county yield data are used to develop forecasted yields and premium rates

valuing option existence and bequest demands for wilderness to assess the relative importance of current costs and future benefits of nuclear waste storage we develop a simple model of bequest value the basic model of nonparternalistic altruism is extended to account for the uncertain nature of the externality

input demand under yield and revenue insurance previous studies disagree on the effects of insurance on fertilizer application rates the effect of increased fertilizer on the probability of low yields primarily determines whether fertilizer and insurance are substitutes or complements we estimate conditional distributions of corn yields to determine if the technical relationship between yields and fertilizer supports the hypothesis that insurance increases optimal application rates our results indicate no support for this hypothesis at all nitrogen fertilizer rates and reasonable levels of risk aversion nitrogen fertilizer and insurance are substitutes suggesting that those who purchase insurance are likely to decrease nitrogen fertilizer applications

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

valuing environmental commodities some recent experiments a general model of consumer behavior is proposed to assess six recent experiments that have attempted to reveal preferences for environmental goals each experiment used a mix of both the techniques and the theory of demand for non market commodities and each was designed to estimate a non market attitude associated with the environment and to analyze potential biases in the techniques the six cases show some consistency in results the linkage within the contingent market between the environmental attribute institutional setting and the bidding instrument must be realistic and accepted by the respondent to avoid biased results possibly the most important result is the replication of results using a traditional property value study and a contingent bidding approach all evidence obtained to date suggests that hedonic studies of property values or wages travel costs and survey techniques all yield values well one order of magnitude in accuracy 41 references 2 tables

a century of research on agricultural markets this article provides a perspective on major innovations in research on agricultural markets over the past century we review research on market structure and performance vertical coordination arrangements and institutions for producer collective action contributions to empirical modeling of agricultural price determination and marketing margins are also evaluated as are innovations in research on spatial market relationships and the role of storage finally we discuss contributions to understanding market information systems and the functioning of market based mechanisms for agri

the health returns of education policies from preschool to high school and beyond the accessibility of quality schools and educational resources for children are key engines of upward mobility in the united states holding the potential to break the cycle of poverty from one generation to the next inequalities in economic status tend to be correlated across generations in part because of intergenerational correlations in health and education rucker c johnson 2009 residential segregation by race and class that leads to unequal access to quality schools is often cited as a culprit in perpetuating inequality in attainment outcomes over the past four decades three major government interventions have had substantial impacts on the provision of school resources and have narrowed black white differences in access to dimensions of school quality i court mandated school desegregation ii state legislation and legal action aimed to change the distribution and level of school funding and iii the expansion of targeted preschool programs for disadvantaged children through head start court ordered school desegregation has been described as the most controversial and ambitious social experiment of the past 50 years human capital health outcomes and inequality

school segregation educational attainment and crime evidence from the end of busing in charlotte mecklenburg we study the end of race based busing in charlotte mecklenburg schools cms in 2001 school boundaries in cms were redrawn dramatically and half of students received a new assignment using addresses measured prior to the policy change we compare students in the same neighborhood that lived on opposite sides of a newly drawn boundary we find that both white and minority students score lower on high school exams when they are assigned to schools with more minority students we also find decreases in high school graduation and four year college attendance for whites and large increases in crime for minority males we conclude that the end of race based busing widened racial inequality despite efforts by cms to mitigate the effect of segregation through compensatory resource allocation jel codes i20 i24

determinants of international university rankings scores this article analyses the relationship between a university s score in international university rankings its expenditure per student and other factors such as university mission size and productive inefficiency we develop an economic model of rankings and universities and estimate this model with data on universities classified in the top 200 by the times higher education supplement ranking of 2007 we find that the elasticity of a university s ranking score for the expenditure per student is between 4 and 9 and that there are no clear signs of inefficiency in production among the top 200 universities university mission and size are also significant predictors of ranking score these results are especially interesting given the relevance attributed to rankings by government officials university directors and students

specification of the logit model the case of valuation of nonmarket goods abstract we address the proper specification of the logit model for estimation of nonmarket commodity demand economic theory is used to show the conditions which must be met by the logit functional form if it is to yield valid estimates of welfare change measures and demand relationships an empirical example is used to illustrate the argument recreational boating data were collected using the contingent valuation method cvm in texas in one instance the demand curve is positively sloped due to the specific functional form chosen the estimated demand curve for the theoretically preferred functional form has the expected negative slope

a satisfactory benefit cost indicator from contingent valuation abstract standard economic concepts are used to develop a model of individual behavior when subject to the constraints of the contingent valuation choice context the model yields refutable consequences that are consistent with previously reported empirical findings including some that have been thought to be anomalous the model is used to show that different contingent valuation formats have predictably different performance characteristics notably the hicksian compensating measures are satisfactory benefit cost indicators when elicited using any one of several formats identified in the text of the formats examined one form of a policy referendum appears to have the most satisfactory characteristics overall we conclude that contingent valuation is a progressing research program

impact of copula choice on the modeling of crop yield basis risk a number of problems in agricultural economics involve modeling joint distributions for which the assumption of multivariate normality may not be warranted yet very little work has been conducted evaluating competing methods for modeling joint dependence we develop a simulation framework to evaluate the bias and efficiency impacts of copula choice in the context of evaluating county to farm basis risk the results suggest significant differences in performance across various copulas and approaches the findings have important implications for risk analysis insurance and policy modeling problems in agriculture regarding the selection of method to model dependence among random variables

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

sixty years after the magic carpet ride the long run effect of the early childhood environment on social and economic outcomes this paper estimates the effect of the early childhood environment on a large array of social and economic outcomes lasting almost 60 years to do this we exploit variation in the living conditions experienced by yemenite children after being airlifted to israel in 1949 we find that children who were placed in a more modern environment i e with better sanitary and infrastructure conditions were more likely to obtain higher education marry at an older age have fewer children and work at age 55 they were also more likely to be assimilated into israeli society to be less religious and have more worldly tastes in music and food however these effects are found mainly for women and not for men we also find an effect on the next generation children who lived in a better environment grew up to have children with more education

parametric and nonparametric statistical modelling of crop yield implications for pricing crop insurance contracts this article considers alternative methods to calculate the fair premium rate of crop insurance contracts based on county yields the premium rate was calculated using parametric and nonparametric approaches to estimate the conditional agricultural yield density these methods were applied to a data set of county yield provided by the statistical and geography brazilian institute ibge for the period of 1990 through 2002 for soybean corn and wheat in the state of parana in this article we propose methodological alternatives to pricing crop insurance contracts resulting in more accurate premium rates in a situation of limited data

cultural transmission and discrimination workers can have good or bad work habits these traits are transmitted from one generation to the next through a learning and imitation process which depends on parents investment in the trait and the social environment where children live if a sufficiently high proportion of employers have taste based prejudices against minority workers we show that their prejudices are always self fulfilled in steady state and minority workers end up having on average worse work habits than majority workers this leads to a ghetto culture affirmative action can improve the welfare of minorities whereas integration can be beneficial to minority workers but detrimental to workers from the majority group

does temporary affirmative action produce persistent effects a study of black and female employment in law enforcement abstract this paper exploits variation in the timing and outcomes of employment discrimination lawsuits against u s law enforcement agencies to estimate the cumulative and persistent employment effects of temporary externally imposed affirmative action aa we find that aa increased black employment at all ranks by 4 5 to 6 2 percentage points relative to national trends we also find no erosion of these employment gains in the fifteen years following aa termination although black employment growth was significantly lower in departments after aa ended than in departments whose plans continued for women in contrast we find only marginal employment gains at lower ranks

do credit constraints favor dirty production theory and plant level evidence abstract this paper explores the effect of credit constraints on production generated pollution emissions i develop a theoretical model wherein polluting firms borrow externally to finance investment in various assets subject to a credit constraint the main insight of the model is that credit constraints distort the composition of assets towards over investment in tangible assets which can be pledged as collateral thereby increasing the intensity of emissions the predictions of the model are tested using a unique dataset consisting of plant level measures of pollution emissions and creditworthiness the empirical results indicate that credit constraints significantly increase pollution emissions even after accounting for the scale effect and the results withstand multiple robustness checks moreover the effect of credit constraints is particularly acute in industries with greater reliance on external credit finally i demonstrate that firm level credit constraints distort the composition of assets and that the composition of assets influences pollution emissions

crop insurance in a political economy an alternative perspective on agricultural policy lawmakers often subsidize farmers in times of financial distress this article models this political impulse as a constraint on government farm policy describing how ex ante government farm insurance can deter ex post disaster relief and improve production incentives by countering the moral hazard that otherwise prevails absent ex ante government policy ex post relief takes the form of revenue insurance which prompts excessive entry into farm production and under production by operating farmers ex ante government policy can raise economic and political welfare by buying out low productivity farmers and offering profitable farmers a combination of revenue insurance price supports and a program participation fee copyright 2003 oxford university press

crop insurance valuation under alternative yield distributions considerable disagreement exists about the most appropriate characterization of farm level yield distributions yet the economic importance of alternative yield distribution specifications on crop insurance valuation has not been well documented the results of this study demonstrate that large differences in expected payouts from popular crop insurance products can arise solely from the parameterization chosen to represent yield distributions the results suggest that the frequently unexamined yield distribution specification may lead to economically significant errors in crop insurance policy rating and assessment of expected payouts from policies

validation of empirical measures of welfare change a comparison of nonmarket techniques since the passing of the flood control act of 1936 the attention of many resource economists has been directed towards measuring the benefits and costs of alternative uses of natural resources increasingly it has been recognized that the value of some of these uses is not explicitly determined through market transactions this has led to the focus of much attention upon the development of nonmarket methods to estimate the value of these uses in the 1940s the groundwork for the travel cost method was established by hotelling prewitt 1949 following this in the 1960s davis initiated the basic foundation for bidding methods davis 1963 which were later to be subsumed under the heading of contingent valuation methods brookshire randall and stoll 1980 schulze d arge and brookshire 1981 thayer 1981 both of these methods will be further discussed below in addition to these two methods a third approach the unit day value method has been recognized as acceptable but not preferred for the valuation of recreational uses of water and related land resources dwyer kelley and bowes 1977 u s water resources council 1979 given the existence of alternative methods of estimating the value of resource uses several obvious questions arise one of the first of these is under what circumstances is each method most appropriate existing literature has focussed sufficiently on this question and pointed out limitations of each especially the travel cost method and unit day value methods brookshire ives and schulze 1976 dwyer kelly and bowes 1977 freeman 1979 mcconnell 1975 randall ives and eastman 1977 schulze d arge and brook

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

a measure of segregation based on social interactions we develop an index of segregation based on two premises 1 a measure of segregation should disaggregate to the level of individuals and 2 an individual is more segregated the more segregated are the agents with whom she interacts we present an index that satisfies 1 and 2 and that is based on agents social interactions the extent to which blacks interact with blacks whites with whites etc we use the index to measure school and residential segregation using detailed data on friendship networks we calculate levels of within school racial segregation in a sample of u s schools we also calculate residential segregation across major u s cities using block level data from the 2000 u s census

u s soybean yields estimation and forecasting with nonsymmetric disturbances national average soybean yields are skewed with a relatively high chance of low yields maximum likelihood estimates support this hypothesis revised forecasts which account for skewed yields are positioned higher than forecasts based on the illusion of a symmetric distribution also yield instability has been increasing steadily the standard deviation of the soybean yield distribution is twenty five percent higher in the late 1980s than it was in the early 1970s

developing experience based premium rate discounts in crop insurance this article addresses the feasibility of implementing an experience based premium rate discount system in crop insurance while adverse selection and moral hazard in crop insurance have been extensively studied in the past discount systems or bonus malus incentives have not to our knowledge been investigated our empirical analysis indicates that a crop insurance discount system could be implemented based on a measure of favorable past insurance experience the estimated average discounts based on the rating methods developed in this study ranged from 5 to 9 depending on the crop being considered

does school quality explain the recent black white wage trend around 1980 the trend toward racial wage convergence essentially stopped i ask whether this break in the convergence trend can be explained by school quality department of education surveys provide earnings data for the high school class of 1972 in 1979 and the class of 1980 in 1986 both linked to data from the respondents high schools by several measures differences between schools attended by blacks and whites were already rather small in the 1970s furthermore i find that measurable school inputs generally have little effect on wages thus school quality explains little of the recent black white wage trend

the planting real option in cash rent valuation after entering into a farmland cash rent contract in the fall a tenant farmer has flexibility over the spring crop choice and the input application level failure to account for these options will bias estimates of what farmers should pay to rent land applying monte carlo simulation methods this study investigates the option values for these choices a multivariate gaussian copula mgc is employed to account for dependence among yields and prices results show that the average cash rent valuation for the real option approach is 33 6 higher than that for the conventional net present value npv method in which the input intensity option is 0 9 crop planting sequence is shown to impact the real option value

is there a viable market for area based crop insurance the performance of area yield insurance and farm level multiple peril crop insurance is analyzed for cotton and soybean production in georgia and south carolina the analysis improves on many previous studies by utilizing actual farm level yield data and by comparing the two types of insurance products not only for actuarially fair premium rates but also for actual unsubsidized and subsidized premium rates results suggest that even in heterogeneous production regions area yield insurance may be a viable alternative to farm level insurance when premium rates for farm level insurance contain large positive wedges

interactions between workers and the technology of production evidence from professional baseball this paper examines how the effort choices of workers within the same firm interact with each other in contrast to the existing literature we show that workers can affect the productivity of their co workers based on income maximization considerations rather than relying on behavioral considerations such as peer pressure social norms and shame theoretically we show that a worker s effort has a positive effect on the effort of co workers if they are complements in production and a negative effect if they are substitutes the theory is tested using panel data on the performance of baseball players from 1970 to 2003 the empirical analysis shows that a player s batting average significantly increases with the batting performance of his peers but decreases with the quality of the team s pitching furthermore a pitcher s performance increases with the pitching quality of his teammates but is unaffected by the batting output of the team these results are inconsistent with behavioral explanations which predict that shirking by any kind of worker will increase shirking by all fellow workers the results are consistent with the idea that the effort choices of workers interact in ways that are dependent on the technology of production these findings are robust to controlling for individual fixed effects and to using changes in the composition of one s co workers in order to produce exogenous variation in the performance of one s peers

intergenerational correlation and social interactions in education we propose a dynastic model where individuals are born into an educated or uneducated environment that they inherit from their parents we study the impact of social interactions on the correlation in parent child educational status independently of any parent child interaction when the level of social interactions is decided by a social planner we show that the correlation in education status between generations decreases very fast as social interactions increase in turn when the level of social interactions is decided by the individuals themselves we show that the intergenerational correlation still decreases although less rapidly than with exogenous social interactions

pricing in microinsurance markets summary microinsurance markets have exhibited strong growth rates in recent years great parts of the industry are however challenged by fundamental issues of providing insurance products one of the most significant of which is pricing risk in this paper we provide a nontechnical analysis of insurance pricing problems and a review of the set of opportunities that can address some of the specific pricing constraints in microinsurance markets a key contribution of this paper is the investigation of conventional techniques as potential solutions for improving the pricing of insurance risk in microinsurance markets

valuing agricultural insurance this paper proposes a method for estimating a farmer s stochastic discount factor that is independent of his or her risk preferences and shows that that stochastic discount factor is appropriate for calculating a farmer s willingness to pay for a crop insurance product an empirical example illustrates how production and price data might be combined with returns data to permit econometric estimation of the stochastic discount factor and the implications of those illustrative results are briefly discussed

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

investigating the performance of different estimation techniques for crop yield data analysis in crop insurance applications we investigate the performance of the ordinary least squares ols m mm and the theil sen ts estimator for crop yield data analysis in crop insurance applications using monte carlo simulations more specifically the performance is assessed with respect to trend estimation prediction of future yield levels and the estimation of expected indemnity payments in agreement with earlier findings other estimators are found to be superior to ols in simple regression problems if yield distributions are outlier contaminated and heteroscedastic while this conclusion is also valid for subsequent applications such as yield prediction and the estimation of expected indemnity payments the difference between the considered estimators becomes less distinct for these applications we find particularly the m estimator to be a good compromise between high breakdown very robust estimators and the very efficient ols estimator because no regression technique dominates all others in all applications and scenarios for error term distributions our results underline that the choice of the estimation technique should be dependent on the purpose of the crop yield data analysis however alternative estimators such as m mm and ts estimator can reduce and bound the risk of unreliable or inefficient crop yield data analysis in crop insurance applications

desegregation and black dropout rates in 1954 the united states supreme court ruled that separate schools for black and white children were inherently unequal this paper studies whether the desegregation plans of the next 30 years benefited black and white students in desegregated school districts data from the 1970 and 1980 censuses suggest desegregation plans of the 1970 s reduced high school dropout rates of blacks by two to three percentage points during this decade no significant change is observed among whites the results are robust to controls for family income parental education and state and region specific trends as well as to tests for selective migration

actuarial fairness of crop insurance rates with constant rate relativities increased availability and demand for low deductible crop insurance policies have increased focus on crop insurance rating methods actuarial fairness cannot be achieved if constant multiplicative factors are used to determine how premiums change as coverage levels increase a comparison of premium rates generated by the factors used by the two most popular crop insurance products with those generated by a standard yield distribution shows that the popular insurance products overcharge for low deductible policies in most counties this overpricing may explain why large premium subsidies were required to induce farmers to move from low deductible to high deductible policies beginning in 2001 crop insurance is by far the most popular risk management tool used by the u s crop producers in 2003 the u s crop insurance program insured more than 200 million acres representing more than 37 billion in value with total premium of over 3 14 billion the two most popular crop insurance products are actual production history aph which provides insurance against low yields and crop revenue coverage crc which is a revenue insurance product both of these products offer coverage in 5 increments from 65 to 85 of expected yield or revenue beginning with the 2001 crop year congress greatly increased subsidy levels to induce producers to purchase more insurance coverage producers responded as expected for example only 2 3 of kansas wheat was insured at levels in excess of 65 in 1998 this proportion rose to 71 6 in 2003 this policy change has increased focus on the methods used by the risk management agency rma of usda to set insurance rates at higher coverage levels aph premium rates are calculated by multiplying the premium rate at the 75 coverage level by a rate

estimating bivariate yield distributions and crop insurance premiums using nonparametric methods modelling crop yield distribution is crucial in crop insurance premium setting the correlation between different crop yields due to rotations or systemic risks requires estimation of joint yield distribution for multiple crops in this article we apply a nonparametric method to estimate bivariate yield distributions using farm level yield data of wheat and corn in shandong province in china then the simulated yields are used to evaluate the expected indemnity of one traditional and one hypothetical crop insurance programme our results reveal that the nonparametric bivariate method is very flexible in shaping the yield probability density functions to estimate local idiosyncrasies and correlation between two crops it is also feasible to simulate the nonparametric yield distributions at a satisfying level of accuracy the simulation results show that the hypothetical two crop insurance contract can be more affordable to farmers than traditional individual crop insurance contracts

does head start improve children s life chances evidence from a regression discontinuity design this paper exploits a new source of variation in head start funding to identify the program s effects on health and schooling in 1965 the office of economic opportunity oeo provided technical assistance to the 300 poorest counties to develop head start proposals the result was a large and lasting discontinuity in head start funding rates at the oeo cutoff for grant writing assistance we find evidence of a large drop at the oeo cutoff in mortality rates for children from causes that could be affected by head start as well as suggestive evidence for a positive effect on educational attainment i introduction head start was established in 1965 as part of the war on poverty to provide preschool health and other social services to poor children age three to five and their families and currently serves over 900 000 children each year at a cost of around 7 billion hhs 2006 this paper provides new evidence on the effects of the head start program on schooling and health by drawing on a new source of variation in program funding spe

the effect of school closings on student achievement abstract many school districts across the country are shutting schools but school closing policies remain a very controversial issue the current study investigates the effects of school closing policies on student achievement by examining over 200 school closings in michigan relative to the previous literature the analysis uses a broader set of school closings to thoroughly investigate heterogeneity in treatment effects based on the performance level of the closed school the results indicate that on average school closings in michigan did no persistent harm to the achievement of displaced students moreover students displaced from relatively low performing schools experience achievement gains the displacement of students and teachers creates modest negative spillover effects on the receiving schools however hence the closing of low performing schools may generate some achievement gains for displaced students but not without imposing spillover effects on a large number of students in receiving schools

bayesian estimation of possibly similar yield densities implications for rating crop insurance contracts the agricultural act of 2014 solidified insurance as the cornerstone of u s agricultural policy the congressional budget office 2014 estimates that this act will increase spending on agricultural insurance programs by 5 7 billion to a total of 89 8 billion over the next decade in light of the sizable resources directed toward these programs accurate rating of insurance contracts is of the utmost importance to producers private insurance companies and the federal government unlike most forms of insurance agricultural insurance is plagued by a paucity of spatially correlated data a novel interpretation of bayesian model averaging is used to estimate a set of possibly similar densities that offers greater efficiency if the set of densities are similar while seemingly not losing any if the set of densities are dissimilar simulations indicate that finite sample performance in particular small sample performance is quite promising the proposed approach does not require knowledge of the form or extent of any possible similarities is relatively easy to implement admits correlated data and can be used with either parametric or nonparametric estimators we use the proposed approach to estimate u s crop insurance premium rates for area type programs and develop a test to evaluate its efficacy an out of sample game between private insurance companies and the federal government highlights the policy implications for a variety of crop state combinations consistent with the simulation results the performance of the proposed approach with respect to rating area type insurance in particular small sample performance remains quite promising

estimation of mixture models using cross validation optimization implications for crop yield distribution modeling a critical issue in identifying an appropriate characterization of crop yield distributions is that the best fitting distribution in an in sample framework is not necessarily the best choice out of sample this study provides a methodology for estimating flexible and efficient mixture models using cross validation that alleviates many of these associated model selection issues the method is illustrated in an application to the rating of group risk insurance products results indicate that nonparametric models often fit best in sample but are inefficient and consistently overstate true rates and vice versa for parametric models the proposed model provides unbiased rates and also has desirable efficiency properties

toward a normative theory of crop yield skewness while the preponderance of empirical studies point to negative crop yield skewness in a wide variety of contexts the literature provides few clear insights on why this is so the purpose of this paper is to make three points on the matter we show formally that statistical laws on aggregates do not suggest a normal yield distribution we explain that whenever the weather conditioned mean yield has diminishing marginal product then there is a disposition toward negative skewness in aggregate yields this is because a high marginal product in bad weather states stretches out the left tail of the yield distribution relative to that of the weather distribution turning to disaggregated yields we decompose unconditional skewness into weather conditioned skewness plus two other terms and study each in turn

is school segregation good or bad it has been well documented that segregation across schools denying access to resources inferior educational production functions and so on exacerbates racial differences in achievement using an individual measure of social connections within schools we have shown that this form of segregation asian kids sitting together in the cafeteria has a substantively unimportant relationship with academic achievement or social behavior in school or later in life there are important caveats to our analysis a our estimates of the relationship between within school segregation and outcomes are not causal and b friendships may not be the only relevant cross race social interaction that occurs within a school

group characteristics evolution arising from asymmetric information in asymmetric information problems agents with less information principals or contractors usually take as given the preferences of agents with more information agents or contractees moreover the distribution of characteristics of contractees is supposed to be invariant in this article we consider a mixed framework of asymmetric information adverse selection followed by moral hazard where those two assumptions are excluded specifically the contractor only knows the current distribution of characteristics and the contractees may change them after signing the contract if this improves their welfare thus we find that the asymmetric information problem leads to a group eect changes of characteristics this feedback defines a sequence of temporary equilibria we provide conditions for the convergence of that sequence to a stationary long run equilibrium we also prove that both temporary equilibrium and long run equilibrium coincide with the equilibrium in classical models of adverse selection and the moral hazard problem vanishes in the long run

the effect of court ordered hiring quotas on the composition and quality of police arguably the most aggressive armative action program ever implemented in the united states was a series of court ordered racial hiring quotas imposed on municipal police departments my best estimate of the eect of court ordered armative action on workforce composition is a 14

spatio temporal modeling of agricultural yield data with an application to pricing crop insurance contracts this article presents a statistical model of agricultural yield data based on a set of hierarchical bayesian models that allows joint modeling of temporal and spatial autocorrelation this method captures a comprehensive range of the various uncertainties involved in predicting crop insurance premium rates as opposed to the more traditional ad hoc two stage methods that are typically based on independent estimation and prediction a panel data set of county average yield data was analyzed for 290 counties in the state of parana brazil for the period of 1990 through 2002 posterior predictive criteria are used to evaluate different model specifications this article provides substantial improvements in the statistical and actuarial methods often applied to the calculation of insurance premium rates these improvements are especially relevant to situations where data are limited

racial segregation and the black white test score gap abstract racial segregation is often blamed for some of the achievement gap between blacks and whites we study the effects of school and neighborhood segregation on the relative sat scores of black students across different metropolitan areas using large microdata samples for the 1998 2001 test cohorts our models include detailed controls for the family background of individual test takers school level controls for selective participation in the test and city level controls for racial composition income and region we find robust evidence that the black white test score gap is higher in more segregated cities holding constant family background and other factors a shift from a highly segregated city to a nearly integrated city closes about one quarter of the raw black white gap in sat scores specifications that distinguish between school and neighborhood segregation suggest that neighborhood segregation has a consistently negative impact while school segregation has no independent effect though we cannot reject equality of the two effects additional tests indicate that much of the effect of neighborhood segregation operates through neighbors incomes not through race per se data on enrollment in honors courses suggest that within school segregation increases when schools are more highly integrated potentially offsetting the benefits of school desegregation and accounting for our findings

relaxing heteroscedasticity assumptions in area yield crop insurance rating this article focuses on the effect of differing heteroscedasticity assumptions on derived premium rates of area yield crop insurance tests of the proportional and absolute heteroscedasticity assumptions are conducted using both in sample and out of sample measures our results suggest that arbitrarily imposing a specific form of heteroscedasticity or homoscedasticity in insurance rate calculations limits actuarial soundness our results have practical implications for the federal crop insurance programs as we reject the traditional rating assumptions for many cotton regions and lower yielding higher risk corn and soybean counties but not in the heart of the cornbelt copyright 2011 oxford university press