control of accumulating stock pollution by heterogeneous producers abstract this paper presents a framework to determine optimal resource allocation over time for the production of a good by heterogeneous producers who generate a stock externality we analyze the optimal intertemporal and quality specific combination of abatement strategies at the source source abatement given by a change in the intensity intensive margin of production and in the chosen technology extensive margin and or removal of existing pollution stock stock abatement the results show how the specifications of the production and the emission functions affect technology adoption and the design of the optimal intertemporal combination of source and stock abatement strategies moreover the paper shows that regulation at the intensive margin cannot be considered as a substitute for a regulation at the extensive margin the paper employs the so called two stage solution approach for solving the resulting quality distributed intertemporal optimal control problem

cost of living inequality during the great recession using detailed barcode level data we construct income group specific price indices for the period of 2004 to 2010 we find substantial differences across income groups arising mainly during the great recession the annual cost of living inflation of the highest quartile has been on average 0 7 percentage points lower than that of the lowest quartile of the income distribution the difference can be explained by the way consumers adjusted their shopping behavior to mitigate the crisis we find that product quality substitution a margin mostly available to richer households is the main mechanism explaining the differences in cost of living inflation our evidence suggests that not accounting for these differences during economic downturns could lead to significant biases in the calculation of inequality and poverty measures jel classifications d12 e31 e32 we thank fernando alvarez erik hurst anil kashyap robert lucas and joseph vavra for their advice and support the paper benefited from comments and suggestions by many others including bong geun choi jorge l garcia jessie handbury sara moreira roberto robatto adriaan ten kate yike wang chen yeh and seminar participants at the university of chicago iea meeting washington university graduate student conference and the midwest macro meeting contacts david argente dargente uchicago edu munseob lee munseob uchicago edu

on the single resource capacity problem for multi item inventory systems in this paper we study multi item inventory systems under a single resource capacity constraint in contrast to most previous approaches we treat the capacity as a decision variable and not as given data this is consistent with many practical cases where additional capacities resources can be acquired rented at some cost profit two solution procedures are developed for deriving an optimal policy within the class of policies that has a fixed cycle for all items with phasing of orders within the cycle these solution procedures can be applied to various types of cost functions as illustrated by an example

threshold management in a coupled economic ecological system abstract economic analysis of optimal ecosystem management in the presence of a threshold has typically ignored the potential for induced behavioral responses this paper contributes to the literature on non convex ecosystem management by considering the implications of a particular behavioral response in a regional economy that of amenity led growth to changes in ecosystem services generated by a lake ecosystem subject to a eutrophication threshold the essential policy challenge is to achieve optimal levels of lake nutrients and urbanization given that improvements to water quality will induce additional migration and urbanization in the region with attendant ecological impacts we show that policies that ignore the recursive relationship between urbanization and water quality unintentionally exacerbate boom bust cycles of regional growth and decline and risk pushing the system towards long run economic decline in contrast the optimal policy accounts for the behavioral feedbacks to improved ecosystem services and balances regional growth and ecological degradation

buying less but shopping more the use of nonmarket labor during a crisis households allocating time between market and non market uses should respond to income variations by adjusting the time devoted to shopping search and other home production activities in this paper we exploit high frequency household expenditure data to examine the use of changes in shopping intensity as a method of mitigating the effects of the 2002 argentine economic crisis although the total quantity and real value of goods purchased fell during the crisis consumers are found to be doing more shopping search this increase in shopping is shown to enable households to seek out lower prices and locate substitutes allowing a given level of expenditure to buy more goods the magnitude and prevalence of these effects suggest that this non market use of labor can be an important coping strategy for households during a recession

estimating the demand for a new technology bt cotton and insecticide policies this article examines the potential demand for bt cotton in the southeast from information gathered in the first year of commercialization we combine revealed preference rp data on adoption of bt cotton varieties with stated preference sp data on willingness to adopt to estimate demand using a double bounded maximum likelihood procedure using estimated demand equations we simulate the costs of reducing conventional insecticide applications through subsidization of bt cotton results indicate that reducing cotton insecticide applications by 40 in the southeast would require a 21 acre subsidy with total annual program costs between 53 million and 60 million

an economic model of soil conservation by introducing soil depth and soil loss into a simple model of agricultural production this paper seeks to determine when the private path of erosion differs from the socially optimal path considering the depletion of soil only and abstracting from the environmental disruption caused by erosion the paper argues that under most institutional arrangements the social and private rates of erosion are the same the paper concludes that public policy should be directed toward reducing erosion only when it leads to significant pollution externalities

global land use implications of first and second generation biofuel targets recently an active debate has emerged around greenhouse gas emissions due to indirect land use change iluc of expanding agricultural areas dedicated to biofuel production in this paper we provide a detailed analysis of the iluc effect and further address the issues of deforestation irrigation water use and crop price increases due to expanding biofuel acreage we use globiom an economic partial equilibrium model of the global forest agriculture and biomass sectors with a bottom up representation of agricultural and forestry management practices the results indicate that second generation biofuel production fed by wood from sustainably managed existing forests would lead to a negative iluc factor meaning that overall emissions are 27 lower compared to the no biofuel scenario by 2030 the iluc factor of first generation biofuels global expansion is generally positive requiring some 25 years to be paid back by the ghg savings from the substitution of biofuels for conventional fuels second generation biofuels perform better also with respect to the other investigated criteria on the condition that they are not sourced from dedicated plantations directly competing for agricultural land if so then efficient first generation systems are preferable since no clear technology champion for all situations exists we would recommend targeting policy instruments directly at the positive and negative effects of biofuel production rather than at the production itself

land use dynamics and the environment we build a benchmark framework to study optimal land use encompassing land use activities and environmental degradation we focus on the spatial externalities of land use as drivers of spatial patterns even if land is immobile by nature location s actions affect the whole space through pollution which flows across locations resulting in both local and global damages in contrast to the previous literature on spatial dynamics we prove that the social optimum problem is well posed i e the solution exists and is unique taking advantage of this result we illustrate the richness of our model by means of a numerical analysis considering a global dynamic algorithm we find that our model reproduces a great variety of spatial patterns related to the interaction between land use activities and the environment in particular we identify the central role of abatement technology as pollution stabilizer allowing the economy to achieve stable steady states that are spatially heterogeneous

economic growth and climate the carbon dioxide problem in contemplating the future course of economic growth in the west scientists are divided between one group crying wolf and another which denies that species existence one persistent concern has been that man s economic activities would reach a scale where the global climate would be significantly affected unlike many of the wolf cries this one in my opinion should be taken very seriously the present article will first give a brief overview of the climatic implications of economic activity with special reference to carbon dioxide and then will present possible strategies for control a more complete report with references to the literature on climatic change is contained in nordhaus 1976 it is thought that the economic activities which most affect climate are agriculture and energy of these the latter is probably more significant is certainly more easily analyzed and will be discussed here in the energy sector emissions of carbon dioxide particulate matter and heat are of significance for the global climate

the econometrics of damage control why specification matters the contribution of damage control agents to production differs fundamentally from that of standard inputs lands labor capital this paper develops an econometric model based on the key characteristics of damage control agents and examines its properties it demonstrates that standard production function specifications overestimate damage control agent productivity and have erroneous implications for the evolution of damage control agent productivity and use in response to changing environments e g the spread of pest resistance it also proposes several alternative specifications and discusses methods for estimating them

dynamic sanitary and phytosanitary trade policy this paper characterizes the optimal use of sanitary and phytosanitary standards to prevent the introduction of harmful pests and diseases through international trade because established pest and disease infestations grow and spread over time their introduction has intertemporal consequences in a dynamic economic model an efficient trade policy balances the costs of sps measures against the discounted stream of the costs of control and social damages that are avoided by using sps measures where future growth of any established infestation is accounted for we examine when phytosanitary trade policy makes good economic sense when it is efficient to provide full protection against pests and diseases and when restrictive but not fully protective trade policy is efficient

agglomeration as local instability of spatially uniform steady states humans exhibit a fundamental propensity to interact for social cultural technological and other reasons in this paper we seek to determine when the propensity to interact expressed in the form of a spatial externality becomes strong enough to induce agglomeration we design an abstract world where the only possible reason for agglomeration is the spatial externality in this world the uniform population distribution is a steady state then to ask under what circumstances does a spatial externality induce agglomeration is to ask under what circumstances does it induce an instability of the steady state anything other than a uniform steady state implies some agglomeration

pattern formation spatial externalities and regulation in coupled economic ecological systems abstract we study the management of ecosystems in which interacting state variables that are affected by management decisions diffuse in space we study pattern formation first in a setting where economic agents maximize myopic profits and ignore spillovers onto agents at other sites and second in the context of a social planner who internalizes these spillovers we compare patterns under these two institutions and study how the differences in the patterns generated by these two institutions impact the design of regulatory schemes to internalize the externalities at the same time we introduce new methods based on fourier series type decompositions that enable us to turn an intractable infinite dimensional optimal control problem into a countable number of finite dimensional optimal control problems as far as we know these methods are new to the economics literature our theory is applied to the management and regulation of a semi arid system

natural resource economics and conservation contributions of agricultural economics and agricultural economists research by agricultural economists on natural resources has been distinguished by an interdisciplinary emphasis and a dynamic perspective it has recognized technological and institutional constraints has been oriented toward solving concrete resource management and policy problems and has emphasized empirical and quantitative analysis agricultural economists have introduced methods for evaluating natural resource conservation efforts for predicting adoption of resource conservation technologies and for designing efficient and sustainable resource management policies they have identified ways of improving land management and preventing land degradation proposed reforms of institutions governing water allocation and water quality and introduced policies for balancing environmental and efficiency considerations in the management of pests biodiversity and livestock diseases their research has had substantial impacts on the formulation of resource conservation policies

household production and the excess sensitivity of consumption to current income empirical research on the permanent income hypothesis pih has found that consumption growth is excessively sensitive to predictable changes in income this finding is interpreted as strong evidence against the pih we propose an explanation for apparent excess sensitivity that is based on a quantitative equilibrium model of household production in which permanent income consumers respond to shifts in sectoral wages and prices by substituting work effort and consumption across home and market sectors although the pih is true this mechanism generates apparent excess sensitivity because market consumption responds to predictable income growth

insurance moral hazard and chemical use in agriculture this paper examines how crop insurance affects corn farmers fertilizer and pesticide use in the u s midwest crop insurance might be expected to affect chemical use because of moral hazard insured farmers may undertake riskier production than do uninsured farmers results suggest that insurance exerts considerable influence on corn farmers chemical use decisions those purchasing insurance applied significantly more nitrogen per acre 19 spent more on pesticides 21 and treated more acreage with both herbicides and insecticides 7 and 63 than did those not purchasing insurance these results suggest that both fertilizer and pesticides may be risk increasing inputs

the economic impacts of climate change evidence from agricultural output and random fluctuations in weather fisher et al 2012 hereafter fhrs have uncovered coding and data errors in our paper deschenes and greenstone 2007 hereafter dg we acknowledge and are embarrassed by these mistakes we are grateful to fhrs for uncovering them we hope that this reply will also contribute to advancing the literature on the vital question of the impact of climate change on the us agricultural sector fhrs main critiques of dg are as follows i there are errors in the weather data and climate change projections used by dg ii the climate change projections are based on the hadley 2 model and scenarios rather than the more recent hadley 3 model and scenarios iii standard errors are biased due to spatial correlation iv the inclusion of state by year fixed effects does not leave enough weather variation to obtain meaningful estimates of the relationship between agriculture profits and weather v storage and inventory adjustment in response to yield shocks invalidate the use of annual profit data and vi fhrs argue that a better specified hedonic model produces robust estimates unlike the results reported in dg four of these critiques have little basis and we respond to them here in the introduction specifically with respect to ii the more recent daily climate predictions were not available when we wrote dg nevertheless the most important issue is providing the reliable estimates of climate change and in this note we report estimates based on the climate model we used in dg and a more recent one that we gained access to in the meantime iii in the primary table on agricultural profits dg reports two sets of standard errors with the first clustered at the county level and the second based on a variance covariance matrix that accounts for spatial correlation using the method proposed in conley 1999 thus the claim of fhrs 2012 seems overblown nevertheless to ease comparisons of papers in this literature this note will adopt the fhrs convention of reporting estimated standard errors clustered at the county and state levels we find that inference is largely unaffected by the choice between these different assumptions about the variance covariance matrix

diffusion induced instability and pattern formation in infinite horizon recursive optimal control this paper develops local stability analysis for deterministic optimal control theory for recursive infinite horizon intertemporal optimization problems where there is a continuum of spatial sites and the state variable can diffuse over these sites we identify sufficient conditions for a type of local instability which emerges from the interaction of the discount rate on the future the curvature of the hamiltonian and the spatial features of the problem we call this phenomenon optimal diffusion induced instability odi we illustrate our analytical methods with three stylized applications the first application is the optimal management of spatially connected human dominated ecosystems the second and third applications are harvesting of spatially interconnected renewable resources jel classification c6 q2

sustainable development challenges to profession of agricultural economics fundamentally sustainable development is a notion of discipline disciplining our current consumption this sense of intergenerational responsibility is a new political principle a virtue that must now guide economic growth the industrial world has already used so much of the planet s ecological capital that the sustainability of future life is in doubt that can t continue brundtland page 5

life cycle prices and production we use scanner data and time diaries to document how households substitute time for money through shopping and home production we document substantial heterogeneity in prices paid for identical goods for the same area and time with older households shopping the most and paying the lowest prices doubling shopping frequency lowers a good s price by 7 to 10 percent we estimate the shopper s price of time and use this series to estimate an elasticity of substitution between time and goods in home production of roughly 1 8 the observed life cycle time allocation implies a consumption series that differs markedly from expenditures

moving back home insurance against labor market risk this paper demonstrates that the option to move in and out of the parental home is a valuable insurance channel against labor market risk which facilitates the pursuit of jobs with the potential for high earnings growth using monthly panel data i document an empirical relationship among coresidence individual labor market events and subsequent earnings growth i estimate the parameters of a dynamic game between youths and parents to show that the option to live at home can account for features of aggregate data for low skilled young workers small consumption responses to shocks high labor elasticities and low savings rates

consumption inequality and family labor supply we examine the link between wage and consumption inequality using a life cycle model incorporating consumption and family labor supply decisions we derive analytical expressions for the dynamics of consumption hours and earnings of two earners in the presence of correlated wage shocks nonseparability progressive taxation and asset accumulation the model is estimated using panel data for hours earnings assets and consumption we focus on family labor supply as an insurance mechanism and find strong evidence of smoothing of permanent wage shocks once family labor supply assets and taxes are properly accounted for there is little evidence of additional insurance jel d12 d14 d91 j22 j31

macroeconomic fluctuations and the allocation of time what are the fundamental driving forces of macroeconomic fluctuations in particular why do people spend more time working in booms and less in recessions these are basic questions of macroeconomics recent thinking has emphasized technology shifts preference shifts and changes in government purchases as likely driving forces it is useful to distinguish atemporal and intertemporal effects of the driving forces under standard assumptions the technology shift has no effect through atemporal channels because income and substitution effects exactly offset a straightforward decomposition of movements of employment attributes most of them to the atemporal effects of preference shifts

the elasticity of substitution between time and market goods evidence from the great recession the elasticity of substitution between time and market goods we document a change in household shopping behavior during the great recession households purchased more on sale larger sizes and generic products increased coupon usage and shopping at discount stores we estimate that the returns to these shopping activities declined during the recession and therefore this behavior implies a significant decrease in households opportunity cost of time using the estimated cost of time and time use data we estimate a high elasticity of substitution between market expenditure and time spent on non market work we find that households smooth a sizable fraction of consumption by varying their time allocation during recessions institutional subscribers to the nber working paper series and residents of developing countries may download this paper without additional charge at www nber org

heterogeneity and aggregation implications for labor market fluctuations we demonstrate that aggregate employment and consumption can increase without a corresponding movement in productivity in a model with heterogeneous agents where the only aggregate disturbance is a productivity shock the interaction between incomplete capital markets and indivisible labor results in a low employment productivity correlation and creates a time varying wedge between the marginal rate of substitution for commodity consumption and hours and productivity our results caution against viewing the measured wedge as an inefficiency due to a failure of labor market clearing or as a fundamental driving force behind business cycles jel d31 e32 j22 j24 j31

the aggregate implications of regional business cycles during the last recession and its aftermath aggregate price growth and aggregate nominal wage growth remained robust despite the high rate of unemployment we document that u s states with weaker labor markets experienced lower price growth lower nominal wage growth and lower real wage growth during the great recession given that reliable measures of local prices do not exist we create our own state price indices using scanner data from the nielsen retail scanner database the main innovation of the paper is the development of an econometric procedure that combines cross region data with aggregate time series data to infer the underlying shocks driving both aggregate and regional business cycles applying our procedure to the great recession we find that a combination of both demand and supply shocks are necessary to account for the joint dynamics of aggregate prices wages and employment during the 2007 2012 period in contrast we find that only demand shocks are needed to explain the cross region variation the results suggest that only using cross region variation to explain aggregate fluctuations is insufficient when shocks do not have a substantive regional component

spatial growth and industry age between 1970 and 2000 employment growth across u s counties exhibited very different patterns in manufacturing and services whereas manufacturing employment growth was negatively related to initial manufacturing employment across the entire distribution of counties service employment growth was positively related to initial service employment for intermediate sized counties this paper presents a theory to rationalize these facts local sectoral growth is driven by technological diffusion across space and depends on the age of the sector the theory correctly predicts the relation between county employment growth and initial county employment in manufacturing at the turn of the 20th century

a multi product continuous review inventory system with stochastic demand backorders and a budget constraint abstract common characteristics of inventory systems include uncertain demand and restrictions such as budgetary or storage space constraints several authors have examined budget constrained multi item stochastic inventory systems controlled by continuous review policies without considering marginal shortage costs existing models assume that purchasing costs are paid at the time an order is placed which is not always the case since in some systems purchasing costs are paid when orders arrive in the latter case the maximum investment in inventory is random since the inventory level when an order arrives is a random variable hence payment of purchasing costs on delivery yields a stochastic budget constraint for inventory this paper models a multi item stochastic inventory system with backordered shortages when estimation of marginal backorder cost is available and payment is due upon order arrival the budget constraint can easily be converted into a storage constraint

the effect of agricultural policies on land use and environmental quality in this paper i consider the environmental quality gains that may be achieved by reducing agricultural income supports a new methodology is developed to estimate land use shares in an application to wisconsin milk price support reductions result in shifts of marginal agricultural land to forest reducing soil erosion and providing off site water quality improvements the environmental benefits are estimated to be at least as large as the decreased welfare burden on consumers and taxpayers indicating a central role for environmental quality considerations in motivating policy reforms and a more efficient means of achieving the environmental quality goals of land retirement programs

spatial agglomeration dynamics this paper develops a model of economic growth and activity locating endogenously on a 3 dimensional featureless global geography the same economic forces influence simultaneously growth convergence and spatial agglomeration and clustering economic activity is not concentrated on discrete isolated points but instead a dynamically fluctuating smooth spatial distribution spatial inequality is a cass koopmans saddlepath and the global distribution of economic activity converges towards egalitarian growth equality is stable but spatial inequality is needed to attain it

optimal harvesting of stochastic spatial resources abstract we characterize the optimal harvest of a renewable resource in a generalized stochastic spatially explicit model despite the complexity of the model we are able to obtain sharp analytical results we find that the optimal harvest rule in general depends upon dispersal patterns of the resource across space and only in special circumstances do we find a modified golden rule of growth that is independent of dispersal patterns we also find that the optimal harvest rule may include closure of some areas to harvest either on a temporary or permanent basis biological reserves reserves alone cannot correct open access but may under sufficient spatial heterogeneity and connectivity increase profits if appropriate harvest controls are in place outside of reserves

valuing biodiversity for use in pharmaceutical research biodiversity prospecting has been touted as a mechanism for both discovering new pharmaceutical products and saving endangered ecosystems it is unclear what values may arise from such activities however evidence from transactions is incomplete and existing theoretical models are flawed we calculate an upper bound on the value of the marginal species even under favorable assumptions this bound is modest slightly modified assumptions lead to drastically lower estimates we extend our findings to the value of the marginal hectare of habitat and find that the incentives for habitat conservation generated by private pharmaceutical research are also at best very modest

economic impacts of marine reserves the importance of spatial behavior abstract marine biologists have shown virtually unqualified support for managing fisheries with marine reserves signifying a new resource management paradigm that recognizes the importance of spatial processes in exploited systems most modeling of reserves employs simplifying assumptions about the behavior of fishermen in response to spatial closures we show that a realistic depiction of fishermen behavior dramatically alters the conclusions about reserves we develop estimate and calibrate an integrated bioeconomic model of the sea urchin fishery in northern california and use it to simulate reserve policies our behavioral model shows how economic incentives determine both participation and location choices of fishermen we compare simulations with behavioral response to biological modeling that presumes that effort is spatially uniform and unresponsive to economic incentives we demonstrate that optimistic conclusions about reserves may be an artifact of simplifying assumptions that ignore economic behavior

optimal ordering quantities for multi products with stochastic demand return cvar model abstract multi product ordering problem with stochastic demand is often optimized by the expected cost reduction or the expected profit improvement in most of previous works moreover risk preference of decision maker is often ignored evidently this approach is impracticable when the corresponding volatility is larger based on the outstanding characteristics of conditional value at risk cvar as a risk measure the paper proposes an optimal order model for multi product with cvar constraints also the model is finally formulated as a linear programming problem the model is simulated for the case of a newsvendor to analyze to what degree it succeeds the solution in fact is bound consistent fully with the decision maker s intuition on return risk decision making finally results of return cvar model and the classical model are compared and shows that return cvar model is more flexible than the classical model

time use during the great recession using data from the american time use survey between 2003 and 2010 we document that home production absorbs roughly 30 percent of foregone market work hours at business cycle frequencies leisure absorbs roughly 50 percent of foregone market work hours with sleeping and television watching accounting for most of this increase we document significant increases in time spent on shopping child care education and health job search absorbs between 2 and 6 percent of foregone market work hours we discuss the implications of our results for business cycle models with home production and non separable preferences jel codes d13 e32 j22

offsetting inventory replenishment cycles abstract the inventory staggering problem is a multi item inventory problem in which replenishment cycles are scheduled or offset in order to minimize the maximum inventory level over a given planning horizon we incorporate symmetry breaking constraints in a mixed integer programming model to determine optimal and near optimal solutions local search heuristics and evolutionary polishing heuristics are also presented to achieve effective and efficient solutions we examine extensions of the problem that include a continuous time framework as well as the effect of stochastic demand

the cyclicality of sales regular and effective prices business cycle and policy implications author s coibion olivier gorodnichenko yuriy hong gee hee abstract we study the cyclical properties of sales regular price changes and average prices paid by consumers effective prices using data on prices and quantities sold for numerous retailers across many us metropolitan areas inflation in the effective prices paid by consumers declines significantly with higher unemployment while little change occurs in the inflation rate of prices posted by retailers this difference reflects the reallocation of household expenditures across retailers a feature of the data which we document and quantify rather than sales we propose a simple model with household store switching and assess its implications for business cycles and policymakers jel d12 e31 e32 l25 l81

the capacitated newsboy problem with random yield the gardener problem abstract this publication is the third in a series of articles by abdel malek et al 2004 exact approximate and generic iterative models for the multi product newsboy with budget constraint international journal of production economics 91 189 198 and abdel malek and montanari 2005 an analysis of multi product newsboy problem with a budget constraint international journal of production economics 97 296 307 which appeared in ijpe addressing issues regarding the newsboy models in this paper models are developed to extend the existing ones to cover random yield scenarios we designate this type of models as the gardener problem the models are based on the application of lagrange multipliers leibniz s rule and newton s method to obtain the optimum solution for the considered random yield and probabilistic demand situations the developed methodologies are applicable to general probability distribution functions examples are given to show the applicability of the developed approach to different probability distributions for both the supply and the demand as well as for interdependent yield structures

implicit prices of soil characteristics for farmland in iowa arguments have long persisted that purchasers pay too much for poor land i e less productive more erosive relative to the higher quality counterpart in other words purchasers are either irrational or poorly informed relative to the differences in land productivity between poor and good farmland similar arguments have been advanced concerning the willingness to pay rent on the part of tenant operators little empirical evidence exists to support or reject this hypothesis farmland appraisals are sometimes cited as evidence to support the contention but such empiricism may indicate more about the quality and biases of appraisers than about the behavior or efficient functioning of the farmland market resolution of this issue is extremely important to the formation of soil conservation policy designed to protect soil productivity irrational behavior on the part of land purchasers may lead one to infer that the market system is failing to recognize adequately the soil productivity consequences of soil erosion if this oversight consistently leads to excessive soil erosion from society s perspective then some form of government intervention may be necessary to protect the welfare of society assuming that such intervention is capable of correcting the market failure

contract choice in modern agriculture cash rent versus cropshare e conomists have expended enormous effort examining the rationale for various contractual arrangements in agriculture particularly sharecropping while economists have made considerable theoretical efforts to understand agricultural contracts few empirical studies have been undertaken the dearth of empirical analyses of agricultural contracts is particularly striking for modern western agriculture this is an important omission not only because the existing empirical work tends to focus on the question of efficiency but also because the theoretical models tend to examine contracts that bear little resemblance to those found in the united states today

2006 presidential address water markets in the west prices trading and contractual forms rising urban and environmental demand for water has created growing pressure to reallocatewaterfromtraditionalagriculturaluses theevolutionofwatermarketshas beenmorecomplicatedthanthoseforotherresources inthispaper wefirstexplainthese differences by examining water rights and regulatory issues second we place our research in the context of the economics literature on water marketing third we present new comprehensive data on prices and the extent nature and timing of water transfers across 12 western states from 1987 to 2005 we find that prices are higher for agriculture to urban trades versus within agriculture trades in part reflecting the differences in marginal values between the two uses prices for urban use are also growing relative to agricultural use markets are responding in that the number of agriculture to urban transactions is rising whereas the number of agriculture to agriculture transfers is not further there is a shift from using shortterm leases to using multiyear leases of water and permanent sales of water rights this pattern underscores the need to consider the amounts of water obligated over time rather than examining only annual flows in assessing the quantities of water traded as is the common practice in the literature considering water obligated over time termed committed water we find significantly more is transferred and the direction of trading is different than if the focus is on annual flows finally the data reveal considerable variation in water trading across the states jel q2 n5 l5 k3

unintended biological invasions does risk vary by trading partner abstract international trade is the primary conduit for unintentional and damaging species introductions but biogeographic heterogeneity and differences in historical trade exposure across trade partners suggest that not all imports are equally risky we develop an analytical model linking exotic species introductions and discoveries to trade volumes the model is estimated using a novel historical data set on global trade and species introductions by region our estimates support theoretical predictions that trade from different regions poses different risks and that the cumulative number of introductions from a region is a concave function of imports for each trade region we then calculate the marginal and cumulative invasion risk from additional trade simple volume restrictions on imports to reduce nis introductions are not advisable based on coarse cost benefit calculations

the economic threshold with a stochastic pest population a real options approach using real options this paper formulates an optimal stopping model for applying pest control measures when the density of a pest population varies randomly a delay between successive pesticide applications is introduced to analyze the farmer s expected marginal cost of reentry this model is applied to the control of a foliar pest of apples via a pesticide and solved numerically a sensitivity analysis shows that the pest density that should trigger pesticide use can vary significantly with the pest density volatility incorporating pest randomness into simple decision rules may thus help better manage the chemicals applied to soils and crops

the newsstand problem a capacitated multiple product single period inventory problem abstract practically all of the many earlier papers on the newsboy problem consider a single newsboy product with no capacity constraint this paper presents formulations and solution procedures for handling multiple newsboy type products under two cases a one resource capacity constraint and b multiple resource constraints for case a we present a necessary extension to the classical hadley whitin result for handling general demand distributions for case b we present a solution procedure that can efficiently handle the common situation where a very large number of products are involved

shopping externalities and self fulfilling unemployment fluctuations we propose a novel theory of self fulfilling fluctuations in the labor market a firm employing an additional worker generates positive externalities on other firms because employed workers have more income to spend and have less time to shop for low prices than unemployed workers we quantify these shopping externalities and show that they are sufficiently strong to create s complementarities in the employment decisions of different firms and to generate multiple rational expectations equilibria equilibria differ with respect to agents rational expectations about future unemployment we show that negative shocks to agents expectations lead to fluctuations in vacancies unemployment labor productivity and the stock market that closely resemble those observed in the us during the great recession

a model of regulated open access resource use abstract this paper develops a model of regulated open access resource exploitation the regulatory model assumes that regulators are goal oriented choosing target harvest levels according to a safe stock concept these harvest quotas are implemented by setting season lengths conditioned on the industry fishing capacity the industry enters until rents are dissipated conditioned on season length regulations harvest levels fishing capacity season length and biomass are determined jointly using parameter estimates from the long regulated north pacific halibut fishery predictions of these variables from the regulated open access model are compared to predictions that arise from the gordon model

bioeconomics of spatial exploitation in a patchy environment abstract this paper presents a model of renewable resource exploitation that incorporates both intertemporal dynamics and spatial movement the model combines the h s gordon vernon smith hypothesis of a rent dissipation process with ricardian notions that resources are exploited across space in a pattern dependent upon relative profitabilities the population structure is characterized in a manner consistent with modern biological ideas that stress patchiness heterogeneity and interconnections among and between patches generally we find the equilibrium patterns of biomass and effort across the system to be dependent upon bioeconomic conditions within each patch and the nature of the biological dispersal mechanism between patches we use simple examples to illustrate how the distribution of effort throughout the system reflects the heterogeneity and the spatial biological linkages

ambient taxes when polluters have multiple choices economic research on environmental policy design has largely been concerned with the merits of emissions based economic incentives e g emissions charges emissions reduction subsidies transferable discharge permits ambient based tax subsidy schemes have drawn considerable interest in nonpoint pollution literature as alternatives to emissions based instruments expanding especially on segerson s seminal article this article examines the optimal design and budget balancing properties of ambient tax subsidy schemes under more realistic assumptions about the dimensions of firms choice sets than prior research

do higher prices for new goods reflect quality growth or inflation much of consumer price index cpi inflation for consumer durables reflects shifts to newer product models that display higher prices not price increases for a given set of goods i examine how these higher prices for new models should be divided between quality growth and price inflation based on a whether consumer purchases shift toward or away from the new models and b whether new model price increases generate higher relative prices that persist through the model cycle i conclude that two thirds of the price increases with new models should be treated as quality growth this implies that cpi inflation for durables has been overstated by almost 2 percentage points per year with quality growth understated by the same magnitude

the optimal carbon sequestration in agricultural soils do the dynamics of the physical process matter the kyoto protocol which came into force in february 2005 allows countries to resort to supplementary activities consisting particularly in carbon sequestration in agricultural soils existing papers studying the optimal carbon sequestration recognize the importance of the temporality of sequestration but overlook the fact that it is an asymmetric dynamic process this paper takes explicitly into account the temporality of sequestration its first contribution lies in the modelling of the asymmetry of the sequestration de sequestration process at a micro level and of its consequences at a macro level its second contribution is empirical we compute numerically the optimal path of sequestration de sequestration for specific damage and cost functions and a calibration that mimics roughly the world conditions we show that with these assumptions sequestration must be permanent and that the error made when sequestration is supposed immediate can be very significant

consumer shopping behavior how much do consumers save this paper documents the potential and actual savings that consumers realize from four particular types of purchasing behavior purchasing on sale buying in bulk at a lower per unit price buying generic brands and choosing outlets how much can and do households save through each of these behaviors how do these patterns vary with consumer demographics we use data collected by a marketing firm on all food purchases brought into the home for a large nationally representative sample of u k households in 2006 we are interested in how consumer choice affects the measurement of price changes in particular a standard price index based on a fixed basket of goods will overstate the rise in the true cost of living because it does not properly consider sales and bulk purchasing according to our measures the extent of this bias might be of the same or even greater magnitude than the better known substitution and outlet biases

aggregate constrained inventory systems with independent multi product demand control practices and theoretical limitations in practice inventory managers are often confronted with a need to consider one or more aggregate constraints these aggregate constraints result from available workspace workforce maximum investment or target service level we consider independent multi item inventory problems with aggregate constraints and one of the following characteristics deterministic leadtime demand newsvendor basestock policy rq policy and ss policy we analyze some recent relevant references and investigate the considered versions of the problem the proposed model formulations and the algorithmic approaches finally we highlight the limitations from a practical viewpoint for these models and point out some possible direction for future improvements

production and investment in natural resource industries there has been a recent tendency for economists to view natural resource scarcity as a diminishing threat to man s existence and his ability to produce an abundant supply of worldly goods see john v krutilla this change in view has emanated from the world s experience of the last few decades with technological development and the absence of any evidence that this rapid accumulation of technical knowledge will cease in some respects one might think that modern technology has removed the need for an economic theory of conservation temporal allocation of natural resources on the other hand conservation of natural resources can now be looked upon with less emotion since the dire consequences of too rapid exploitation are no longer a threat the question of conservation is thus a cold economic problem removed from many of its older value connotations there is indeed considerable effort taking place in the economics profession to fill this need for a quantitative economic theory of conservation however with one exception vernon smith focus has been limited to specific resources earlier works by lewis c gray and harold hotelling concerning the theory of the mine have recently been extended in numerous papers see r cummings and 0 burt richard l gordon anthony scott 1967 problems associated with petroleum production are considered in paul davidson and the fishery is considered in j a crutchfield and arnold zellner h scott gordon james quirk and vernon smith anthony scott 1955 and ralph turvey an extensive literature exists on the temporal allocation of groundwater two recent contributions are gardner brown and charles b mcguire and burt a logical problem has been encountered however in efforts to examine the optimum allocation of a natural resource over time without explicitly considering the rate of investment associated with resource use this difficulty stems from the long life of many capital items used in the process of exploiting the natural resource earlier studies have either tacitly or explicitly amortized costs of investment associated with resource use and proceeded as though all costs of production were essentially variable smith was the first to explicitly bring capital investment into a production model for natural resources and his work was followed by the authors where only exhaustible resources were considered more recently quirk and smith have introduced a dynamic model of the fishery in which capital investment is treated explicitly it seems then that there is a need for a comprehensive model for simultaneously optimizing the rate of resource use and investment in natural resource industries

the economics of a public fund for environmental amenities a study of crp contracts the problem of targeting crp purchases to buy environmental amenities under productivity and environmental heterogeneity is considered gini coefficients and lorenz curves are used to measure the effectiveness of spending under alternative targeting criteria the environmental benefits considered are water erosion wind erosion surface water quality and wildlife habitat the three alternative targeting criteria examined include purchasing land according to i the benefit to cost ratio ii the level of benefits and iii the level of cost results indicate that the degree of variability and correlation determine the extent to which suboptimal targeting achieves a significant portion of available environmental benefits

spatial externalities and agglomeration in a competitive industry abstract we introduce spatial spillovers as an externality in the production function of competitive firms operating within a finite spatial domain under adjustment costs spillovers may attenuate with distance and the overall externality could contain positive and negative components with the overall effect being positive we show that when the spatial externality is not internalized by firms spatial agglomerations may emerge endogenously in a competitive equilibrium the result does not require increasing returns at the private or the social level increasing marginal productivity of private capital with respect to the externality or location advantages in fact agglomerations may emerge with decreasing returns to scale declining marginal productivity of private capital with respect to the externality and no location advantage the result depends on the interactions between the structures of production technology and spatial effects as shown in the paper no agglomerations emerge at the social optimum when spillovers are internalized and diminishing returns both from the private and the social point of view prevail numerical experiments with cobb douglas and ces technologies and an isoelastic demand confirm our theoretical predictions

farm level economic analysis incorporating stochastic environmental risk assessment a farm level risk programming framework is presented which evaluates income environmental risk tradeoffs this framework uses a time series of environmental risk indices to incorporate the stochastic multiattribute characteristics of environmental outcomes associated with agricultural production practices the model is applied to a representative farm in the oklahoma panhandle region of the central high plains results indicate that expected income is sensitive to nitrate loading restrictions and relatively less sensitive to pesticide loading restrictions results also indicate that prescriptions derived using deterministic environmental risk measures may ignore significant probabilities of exceeding an environmental standard

home production labor wedges and international business cycles non separabilities due to home production break the link between market consumption and its marginal utility and help explain several stylized facts of the open economy in an estimated two country model with complete asset markets in which home production generates a labor wedge that mimics its empirical counterpart output is more correlated than consumption across countries labor inputs and labor wedges are positively correlated across countries and relative market consumption is negatively related to the real exchange rate evidence from time use surveys corroborates some of the predictions of the model

inventory service level measures convexity and approximation we argue that standard approximations for two often used inventory service level measures may perform poorly in many situations then we confirm the long standing conjecture that the relatively exact formulas for these quantities are convex functions of the relevant control variables both results suggest the exact expressions should be seriously considered in practical work

economics of controlling invasive species a stochastic optimization model for a spatial dynamic process we analyze the dynamic process of invasive species control in a spatially explicit and stochastic setting an integer optimization model is applied to identify optimal strategies to deal with invasive species at a steady state optimal strategies depend on the spatial location of invasion as well as on stochastic characteristics of spread and control previous studies of invasive species control have been stochastic or spatial but not both we model a landscape as consisting of multiple cells each of which may be subject to border control or eradication within the cell optimal strategies from the model are characterized as eradication containment or abandonment of control representing the rate of species spread as stochastic rather than deterministic results in less intensive control becoming optimal at equilibrium the optimal strategy may switch from eradication to containment or from containment to abandonment if an infestation occurs at the boundary of the region within which it may spread it is more likely to be optimal to eradicate or contain the species compared to an infestation in the interior of the region if the effectiveness of border control is stochastic then containment is not feasible in the long term but it is still optimal as a temporary measure in some scenarios

robust multi item newsboy models with a budget constraint abstract in this paper we present robust newsboy models with uncertain demand the traditional approach to describing uncertainty is by means of probability density functions in this paper we present an alternative approach using deterministic optimization models we describe uncertainty using two types of demand scenarios namely interval and discrete scenarios for interval demand scenarios we only require a lower and an upper bound for the uncertain demand of each item while for discrete demand scenarios we require a set of likely demand outcomes for each item using the above scenarios to describe demand uncertainty we develop several minimax regret formulations for the multi item newsboy problem with a budget constraint for the problems involving interval demand scenarios we develop linear time optimal algorithms we show that the corresponding models with discrete demand scenarios are np hard and that they are solvable by dynamic programming finally we extend the above results to the case of mixed scenarios where the demand of some of the items is described by interval scenarios and the demand of the remaining items is described by discrete scenarios

landing fees vs harvest quotas with uncertain fish stocks a revised version of this paper was published in the journal of environmental economics and management volume 43 issue 2 march 2002 pages 325 338

offsetting inventory replenishment cycles to minimize storage space abstract in a recent paper murthy n n benton w c rubin p a 2003 offsetting inventory cycles of items sharing storage european journal of operational research 150 304 319 discussed the problem of offsetting inventory replenishment cycles of several items in order to minimize the maximum required storage space they analyzed the case where replenishment cycles are given integer multiples of a basic period and proposed a heuristic to solve the problem while they provided a good analysis of the considered problem the proposed heuristic produces less interesting results in the following a simpler more efficient and easier to implement heuristic is proposed numerical results are provided to prove its superiority

multi product newsvendor problem with value at risk considerations abstract we consider the single period stochastic inventory newsvendor problem with downside risk constraints the aim in the classical newsvendor problem is maximizing the expected profit this formulation does not take into account the risk of earning less than a desired target profit or losing more than an acceptable level due to the randomness of demand we utilize value at risk var as the risk measure in a newsvendor framework and investigate the multi product newsvendor problem under a var constraint to this end we first derive the exact distribution function for the two product newsvendor problem and develop an approximation method for the profit distribution of the n product case n 2 a mathematical programming approach is used to determine the solution of the newsvendor problem with a var constraint this approach allows us to handle a wide range of cases including the correlated demand case that yields new results and insights the accuracy of the approximation method and the effects of the system parameters on the solution are investigated numerically

on modeling and interpreting the economics of catastrophic climate change with climate change as prototype example this paper analyzes the implications of structural uncertainty for the economics of low probability high impact catastrophes even when updated by bayesian learning uncertain structural parameters induce a critical tail fattening of posterior predictive distributions such fattened tails have strong im plications for situations like climate change where a catastrophe is theoretically possible because prior knowledge cannot place sufficiently narrow bounds on overall damages this paper shows that the economic consequences of fat tailed structural uncertainty along with unsureness about high temperature damages can readily outweigh the effects of discounting in climate change policy analysis

quantifying quality growth we introduce an instrumental variables approach to estimate the importance of unmeasured quality growth for a set of 66 durable consumer goods our instrument is based on predicting which of these 66 goods will display rapid quality growth using pooled cross relatively sections of households in the 1980 through 1996 u s consumer expenditure surveys we estimate quality engel curves for 66 durable consumer goods based on the extent richer households pay more for a good conditional on purchasing we use the slopes of these curves to predict the rate of quality upgrading just as if households are ascending these quality engel curves over time we find that the average price paid rises faster for goods with steeper quality slopes bls prices likewise increase more quickly for goods with steeper quality slopes suggesting the bls does not fully net out the impact of quality upgrading on prices paid we estimate that quality growth averages about 3 7 per year for our goods with about 60 of this or 2 2 per year showing up as higher inflation rather than higher real growth