optimal nonparametric estimation of first price auctions this paper proposes a general approach and a computationally convenient estimation procedure for the structural analysis of auctioni data considering first price sealed bid auction models within the independent private value paradigm we show that the underlying distribution of bidders private values is identified from observed bids and the number of actual bidders without any parametric assumptions using the theoiy of minimax we establish the best rate of uniform convergence at which the latent density of private values can be estimated nonparametrically from available data we then propose a two step kernel based estimator that converges at the optimal rate

impact of modern agricultural technologies on smallholder welfare evidence from tanzania and ethiopia this paper evaluates the potential impact of adoption of improved legume technologies on rural household welfare measured by consumption expenditure in rural ethiopia and tanzania the study utilizes cross sectional farm household level data collected in 2008 from a randomly selected sample of 1313 households 700 in ethiopia and 613 in tanzania the causal impact of technology adoption is estimated by utilizing endogenous switching regression this helps us estimate the true welfare effect of technology adoption by controlling for the role of selection problem on production and adoption decisions our analysis reveals that adoption of improved agricultural technologies has a significant positive impact consumption expenditure in per adult equivalent terms in rural ethiopia and tanzania this confirms the potential role of technology adoption in improving rural household welfare as higher consumption expenditure from improved technologies translate into lower poverty higher food security and greater ability to withstand risk an analysis of the determinants of adoption highlighted inadequate local supply of seed access to information and perception about the new cultivars as key constraints for technology adoption

technology adoption under seed access constraints and the economic impacts of improved pigeonpea varieties in tanzania dry land legumes well adapted to drought prone areas have largely been neglected in the past despite the good opportunities they offer for income growth and food and nutritional security for the poor this study evaluated the adoption and impact of two farmer and market preferred and disease resistant pigeonpea varieties that were developed and promoted in semi arid tanzania the new varieties were resistant to fusarium wilt a fungal disease devastating the crop however farmers wanting to adopt new varieties did not adopt due to seed access constraints and under developed seed delivery systems adoption of new varieties is therefore analyzed using an augmented double hurdle model that allows estimating variety adoption conditional on seed access thresholds accounting for the additional information on sample separation the study identifies the crucial role of seed access local supply extension education participatory decision making capital and household assets in determining adoption the social economic benefits of the technology and policies for improved seed access were further analyzed using the extended economic surplus method dream model even under restrictive assumptions overall discounted benefits were found to be quite attractive indicating the need for additional efforts to scale up the success story analysis of changes in research benefits from relaxing the seed access constraint showed that net gains would increase by up to 30 if farmer access to improved seeds can be assured smallholder farmers are the major beneficiaries along with consumers and rural net buyers who gain from productivity induced lower market prices

testing for affiliation in first price auctions using entry behavior in this article we show that affiliation among potential bidders private information either private signals or entry costs leads to affiliation among their entry decisions we propose a test for affiliation among potential bidders private information based on the implication of affiliation on the entry behavior which is general and widely applicable to various scenarios the test is implemented using the simulation based method we then apply our method to timber sales in the oregon department of forestry and find a small but strongly significant level of affiliation among all timber companies

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

equilibrium in auctions with entry the authors model entry incentives in auctions with risk neutral bidders and characterize a symmetric equilibrium in which the number of entrants is stochastic the presence of too many potential bidders raises coordination costs that detract from welfare the authors show that the seller and society can benefit from policies that reduce market thickness i e the relative abundance of buyers their analysis extends well known revenue equivalence and ranking theorems but also demonstrates that variations in the auction environment affect optimal policies e g reservation prices in ways not anticipated by models that ignore entry copyright 1994 by american economic association

the impact of research led agricultural productivity growth on poverty reduction in africa asia and latin america abstract twenty percent of the world s population or 1 2 billion live on less than 1 per day 70 of these are rural and 90 are in asia and sub saharan africa research led technological change in agriculture generates sufficient productivity growth to give high rates of return in africa and asia and has a substantial impact on poverty currently reducing this number by 27 million per annum whereas productivity growth in industry and services has no impact the per capita cost of poverty reduction by means of agricultural research expenditures in africa is 144 and in asia 180 or 50 cents per day but this is covered by output growth by contrast the per capita cost for the richer countries of latin america is over 11 000

structural analysis of nonlinear pricing this paper proposes a new methodology for analyzing nonlinear pricing data we establish identification of the model primitives with a known tariff and characterize the model restrictions on observ

neglected effects on the uses side even a uniform tax would change relative goods prices fundamental tax reform may change relative prices of consumption goods and may therefore have important effects on the uses side that are ignored by most general equilibrium simulation models for a uniform rate of tax in our model results on the uses side are driven by the nonuniform tax system being replaced similar effects occur under any uniform and comprehensive tax reform whether the current system is replaced by a consumption tax a wage tax or a pure income tax any such reform that eliminates the current preferential treatment of housing would impose an additional one time levy on the elderly and any reform that eliminates the current double taxation of corporate capital would reduce the relative prices of corporate capital intensive goods bought by the poor this abstract was borrowed from another version of this item

forecasting resource allocation decisions under climate uncertainty fire suppression with assessment of net benefits of research making input decisions under climate uncertainty often involves two stage methods that use expensive and opaque transfer functions this article describes an alternative single stage approach to such decisions using forecasting methods the example shown is for preseason fire suppression resource contracting decisions faced by the united states forest service two stage decision tools have been developed for these decisions and we compare the expected gains to the agency in terms of reduced personnel costs of the single stage model over the two stage model existing hiring decisions and decisions that would have been made given perfect foresight about wildfire activity our analysis demonstrates the potential gains to versions of our single stage model over existing hiring decisions equivalent to a benefit cost ratio of 22 the research also identified additional gains accruing from imposing biases on the single stage model associated with asymmetric penalties from contracting decisions copyright 2008 oxford university press

productivity and land enhancing technologies in northern ethiopia health public investments and sequential adoption the adoption of more efficient farming practices and technologies that enhance agricultural productivity and improve environmental sustainability is instrumental for achieving economic growth food security and poverty alleviation in sub saharan africa our research examines the interaction between public investments community health and adoption of productivity and land enhancing technologies by households in the northern ethiopian state of tigray agricultural technology adoption decisions are modeled as a sequential process where the timing of choices can matter we find that time spent sick and opportunity costs of caring for sick family members are significant factors in adoption sickness through its impact on household income and labor allocation decisions for healthcare and other activities significantly reduces the likelihood of technology adoption our findings suggest that agencies working to improve agricultural productivity and land resource conservation should consider not only the financial status of potential adopters but also their related health situation

measuring the impacts of agricultural research on poverty reduction policymakers are increasingly calling upon agricultural research managers to consider poverty reduction objectives when making resource allocations the authors present a simple method to measure the impact of agricultural research on the poor this method has the advantage that it presents the results in a manner consistent with commonly used measures of poverty this consistency and focus should facilitate and enhance dialogue between policymakers and research managers when deciding on resource allocations and assessing impacts on poverty reduction an illustrative application is presented using data from malawi

economic effects of fundamental tax reform brookings institution the tax system profoundly affects countless aspects of private behavior it is a powerful policy influence on the distribution of income and it is the one aspect of government that almost every citizen cannot avoid with tax reform high on the political agenda this book brings together studies of leading tax economists and lawyers to assess the various reform proposals and examine the effects of tax reform in several distinct areas together these studies and comments on them present a balanced evaluation of professional opinion on the issues that will be critical in the tax reform debate the book addresses annual and lifetime distributional effects saving investment transitional problems simplification home ownership and housing prices charitable groups international taxation financial intermediaries and insurance labor supply and health insurance

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

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

agricultural technology crop income and poverty alleviation in uganda summary this paper evaluates the ex post impact of adopting improved groundnut varieties on crop income and poverty in rural uganda the study utilizes cross sectional data of 927 households collected in 2006 from seven districts in uganda using propensity score matching methods we find that adopting improved groundnut varieties technology significantly increases crop income and reduces poverty the positive and significant impact on crop income is consistent with the perceived role of new agricultural technologies in reducing rural poverty through increased farm household income this study supports broader investment in agriculture research to address vital development challenges reaching the poor with better technologies however requires policy support for improving extension efforts access to seeds and market outlets that simulate adoption

ex ante agricultural research evaluation with site specific technology generation the case of sorghum in kenya abstract agricultural commodity research has very site specific productivity impacts crucial determinants of the magnitude and distribution of research benefits include agroecological conditions for technology generation and adoption as well as commodity market structure this paper presents a process for ex ante research evaluation which accounts for these factors with a dynamic spatial multi market model simulation results based on sorghum research in kenya demonstrate that potential research benefits can vary dramatically across program research target zones in kenya however population induced demand growth not technological development will have the greatest influence on future sorghum markets

the impact of improved maize varieties on poverty in mexico a propensity score matching approach summary this study examines the adoption of improved maize germplasm in oaxaca and chiapas in mexico it employs a propensity score matching approach to analyze the impact of the adoption of improved maize varieties on household income and poverty reduction using cross sectional data of 325 farmers from the two regions the findings reveal a robust positive and significant impact of improved maize variety adoption on farm household welfare measured by per capita expenditure and poverty reduction specifically the empirical results suggest that adoption of improved maize varieties helped raise household per capita expenditure by an average of 136 173 mexican pesos thereby reducing their probability of falling below the poverty line by roughly 19 31

the poverty impacts of improved cowpea varieties in nigeria a counterfactual analysis adoption of improved agricultural technologies has long been recognized as critical for reducing poverty through increased productivity incomes and asset accumulation using a nationally representative survey data from a sample of over 1500 households in nigeria this paper evaluates the impacts of adoption of improved cowpea varieties on income and asset poverty reduction using an endogenous switching regression model the results showed that adoption of improved cowpea varieties increased per capita household income and asset ownership by 17 and 24 percentage points respectively the results based on the observed and counterfactual income and asset distributions further showed that adoption reduced both income poverty and asset poverty by 5 percentage points the paper concludes with a discussion of the policy options for increasing adoption and impacts of improved cowpea varieties in nigeria

bidder collusion at forest service timber sales allegations of bidder collusion at forest service timber sales in the pacific northwest were common in the 1970s of course prices may be low for reasons other than collusion we formulate an empirical model that allows for both bidder collusion and supply effects and in which we control for demand conditions noncooperative behavior in which a single unit is sold the standard auction model is a special case it is found to be definitively outperformed by a model of collusion we also find that supply effects are dominated by collusion in determining the winning bids in the market

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

estimating risk aversion from ascending and sealed bid auctions the case of timber auction data estimating bidders risk aversion in auctions is a challeging problem because of identification issues this paper takes advantage of bidding data from two auction designs to identify nonparametrically the bidders utility function within a private value framework in particular ascending auction data allow us to recover the latent distribution of private values while first price sealed bid auction data allow us to recover the bidders utility function this leads to a nonparametric estimator an application to the us forest service timber auctions is proposed estimated utility functions display concavity which can be partly captured by constant relative risk aversion

poverty reduction effects of agricultural technology adoption a micro evidence from rural tanzania abstract this article evaluates the impact of adoption of improved pigeonpea technologies on consumption expenditure and poverty status using cross sectional data of 613 households from rural tanzania using multiple econometric techniques we found that adopting improved pigeonpea significantly increases consumption expenditure and reduces poverty this confirms the potential role of technology adoption in improving household welfare as higher incomes translate into lower poverty this study supports broader investment in agriculture research to address vital development challenges reaching the poor with better technologies however requires policy support for improving extension efforts access to seeds and market outlets that stimulate adoption

asymmetry in procurement auctions evidence from snow removal contracts differences in cost efficiency and productivity across firms may introduce asymmetries in procure ment auctions relying on a structural approach this article investigates potential asymmetry among firms bidding for snow removal contracts in montrthe empirical results show that firms located in close proximity have a cost advantage relative to other firms in the most urbanised part of montrbecause of prohibitive equipment storage costs the extent of inefficiency due to asym metry is empirically assessed various policy experiments are performed a bidding preference policy shows that the city could expect to reduce its costs for allocating snow removal contracts when bidders willingness to pay depends in part on observable variables the princi pal s interest is not best served by creating a level auction playing field this article studies procurement auctions for snow removal contracts in montrit investigates the degree to which companies in disadvantageous locations should win even if they do not submit the lowest bid from the submitted bids a novel empirical methodology estimates the extent of cost variation across firms along with its variation within loca tion although the dispersion is substantial the gain from treating bidders unequally is limited when observed individual characteristics affect the firms costs and their bidding strategies all bidders cannot be treated alike these differences in characteristics or asymmetries among bidders may arise from their size as noted by laffont et al 1995 their capacity constraints as in jofre bonet and pesendorfer 2003 or the possession of better information as in hendricks and porter 1988 and hendricks et al 1994

auctions with resale markets an application to u s forest service timber sales when bidders anticipate an opportunity for resale trade the value of winning an auction is determined in part by the option values of buying and selling in the secondary market one implication is that a bidder s willingness to pay at an auction increases with the expected level of competition between resale buyers empirical evidence from auctions of timber contracts supports this prediction and rejects standard models that ignore resale the estimated effect is smaller after policy changes expected to diminish the prevalence of resale additional evidence supports the predicted presence of a common value element introduced by the resale opportunity

agricultural technology adoption and child nutrition enhancement improved maize varieties in rural ethiopia adoption of improved crop varieties can lead to multiple benefits to farm households including increased productivity incomes and food consumption however possible impacts of adoption on child nutrition outcomes are rarely explored in the literature this article helps bridge this gap through an impact assessment of the adoption of improved maize varieties imvs on child nutrition outcomes using a recent household survey from rural ethiopia the conceptual linkage between imv adoption and child nutrition is first established using an agricultural household model instrumental variable estimation suggests the overall impacts of adoption on child height for age and weight for age z scores to be positive and significant quantile instrumental variable regressions further reveal that such impacts are largest among children with poorest nutrition outcomes finally by combining a decomposition procedure with system of equations estimation it is found that the increase in own produced maize consumption is the major channel through which imv adoption affects child nutrition

sizing up social science research economists and especially agricultural economists have invested considerable amounts of time and intellectual effort in the question of measuring the benefits of and returns to scientific research and development extensive sets of estimation techniques have been developed and healthy and productive debates about estimated rates of return to science research and development r d and optimal science r d policies have been carried out by economists and agricultural economists in contrast a virtual methodological and empirical vacuum exists in the economics literature with respect to the benefits of and returns to social science research and more especially agricultural economics research this void poses a serious problem for agricultural economics research in the current public research policy environment policy makers and directors of research institutions are confronted with increasingly tight public budgets for r d part of their response has been to seek credible ex ante estimates of

identification of standard auction models this paper presents new identification results for models of first price second price ascending english and descending dutch auctions we consider a general specification of the latent demand and information structure nesting both private values and common values models and allowing correlated types as well as ex ante asymmetry we address identification of a series of nested models and derive testable restrictions enabling discrimination between models on the basis of observed data the simplest model symmetric independent private values is nonparametrically identified even if only the transaction price from each auction is observed for richer models identification and testable restrictions may be obtained when additional information of one or more of the following types is available i the identity of the winning bidder or other bidders ii one or more bids in addition to the transaction price iii exogenous variation in the number of bidders iv bidder specific covariates while many private values pv models are nonparametrically identified and testable with commonly available data identification of common values cv models requires stringent assumptions nonetheless the pv model can be tested against the cv alternative even when neither model is identified

the long run dynamics of fundamental tax reform in this paper we analyze the impact of fundamental tax reform on the dynamics of u s economic growth over the next quarter century we consider two alternative approaches to tax reform the first is a flat rate consumption tax similar to the one introduced by majority leader dick armey and senator richard shelby in the 104th congress the second is an income base value added tax also with a flat rate these taxes would be substituted for existing individual and corporate income taxes at federal state and local levels a full description of the two proposals is given by the joint committee on taxation 1996 our simulations of u s economic growth under alternative tax policies are based on an intertemporal equilibrium model of the u s economy we have continuously revised and updated this model since it was first published in 1990 version 9 incorporates the detailed representation of the u s tax structure presented by jorgenson and kun young yun 1991 in tax reform and the cost of capital we present a detailed description of the model and summarize more than a dozen applications in jorgenson and wilcoxen 1993 our model of u s economic growth is disaggregated to the 35 industries listed below in addition the model distinguishes among 1 344 types of households disaggregated by family size age and gender of household head region of residence race and urban versus rural location the model is built around submodels of investment and saving based on rational expectations the price of investment goods in every period is based on expectations of future capital service prices and discount rates that are fulfilled by the solution of the model in order to analyze the economic impact of changes in tax policy we simulate the growth of the u s economy with and without changes

targeting poverty alleviation in priority setting for agricultural research abstract this paper provides a brief overview of research priority setting methods at various levels in national research systems noting the changing emphasis from supply to demand driven approaches at both macro and micro levels of priority setting the scope for incorporating a poverty dimension into priority setting is then reviewed within a general framework that recognises the complexity of the link between research investments and poverty alleviation the effectiveness of this targeting is likely to be very situation specific a case study of macro priority setting in pakistan shows the limited scope to target benefits to the poor through re allocation of research resources among commodities relative to a ranking based on the efficiency objective given present knowledge enhancing the efficiency and effectiveness of research systems in promoting broad based technical change should be emphasised more than major efforts to target poverty directly this will involve a combination of supply and demand driven approaches to priority setting at different levels in the research system that will enhance both the efficiency and poverty alleviation impacts of research

a nonparametric test for comparing valuation distributions in first price auctions this article proposes a nonparametric test for comparing valuation distributions in first price auctions our test is motivated by the fact that two valuation distributions are the same if and only if their integrated quantile functions are the same our method avoids estimating unobserved valuations and does not require smooth estimation of bid density we show that our test is consistent against all fixed alternatives and has nontrivial power against root n local alternatives monte carlo experiments show that our test performs well in finite samples we implement our method on data from u s forest service timber auctions

agricultural research priority setting under multiple objectives an example from zimbabwe abstract strategic priorities are assessed for the agricultural research system in zimbabwe in a situation characterized by multiple objectives farm types and agro ecological zones economic surplus analysis is used to rank research programs by commodity and research program areas in total and disaggregated by large and small farms in high and low potential regions no funding current funding and 50 more funding are allowed for each program in the analysis an optimal research portfolio is developed first with all weight placed on efficiency and second with increasing weights placed on benefits going to small holder farmers even with no additional weight placed on small holders research programs for both small farms and low potential areas enter into the optimal research portfolio as more emphasis is given to small holders the reduction in overall efficiency gained due to research is relatively modest maize and cotton were the highest ranked commodity research programs of the 36 commodities considered for both large and small farms agronomy and soils research are relatively more important for small holders while plant breeding and crop protection are relatively more important for large scale farmers