renewable natural resource management and use without markets natural resources by their nature are not readily bent to the status of private property efficient resource use is complicated by jurisdictional externalities public goods non use values and beneficiaries spatially separated from the location of resources the task is made more challenging by ecological complexity that obscures cause benefits and effects costs and dramatic time lags between individual actions and subsequent social consequences that together with substantial uncertainty introduce the chance of irreversibilities resource economists have played a major role in the literature on externalities the development of individual transferable quotas non market valuation techniques and common property management

property rights externalities and resource degradation locating the tragedy abstract resource degradation in the third world is largely driven by the demands of farm households for fuelwood and land for agriculture since resources are often controlled through indigenous systems of property the tragedy of the commons has been used to explain resource degradation as a result private property is suggested as a solution to resource degradation a dynamic model capable of examining household incentives for resource use under private and common property is developed results of the model reject the conventional wisdom that gives rise to the presumed optimality of private individual property in natural resources and the correlated indictment of group management regimes

rational panics and stock market crashes abstract this paper offers an explanation for stock market crashes which focuses on the role of rational but uninformed traders we show that uninformed traders can precipitate a price crash because as prices decline they surmise that informed traders received negative information which leads them to reduce their demand for assets and drive the price of stocks even lower the model yields several implications such as that crashes can occur even when the fundamentals are strong and that the magnitude of the crash depends on the fraction of uninformed investors and the amount of unsophisticated passive investing present in the market

the male marital wage premium sorting vs differential pay the authors examine whether male marital and parenthood premia arise due to differential pay by employers or from differential sorting of employees on occupations and establishments they investigate these premia using matched employee employer data from the period 1979 96 in norway a country with increased pressures on men to be more active in the family sphere and in which public policy has aimed at remaking the family institution we find that the effect of marriage and to a lesser extent of children occurs mostly through sorting on occupations and occupation establishment units the role of differential pay from employers is marginal in explaining the marital and parenthood premia results assessing within individual changes in wages suggest that about 80 of the marital premium is due to selection the men who eventually marry and or have children sort into the higher paying occupations and occupation establishment units even prior to marriage and parenthood

institutional constraints and deforestation an application to mexico 1 introduction in many tropical regions a key factor influencing deforestation is thought to be the lack of effective property rights and other institutional structures controlling access to and use of forests 1 where such institutions exist they limit access to and conversion of forest land thus acting as a deterrent to deforestation in the absence of formal ownership rules traditional common property regimes in some forested regions have also proven to be effective in controlling the open access deforestation problem gibson 2001 larson and bromley 1990 richards 1997 in short formal and informal institutions can influence the process of forest loss by imposing increased costs of conversion on farmers who clear forest land this article is concerned with analyzing the role of formal and informal institutions as constraints on the conversion of forest land to agriculture in developing countries the perspective on institutions adopted here follows the approach of north 1990 who defines institutions as humanly devised constraints that shape human interaction and that affect the performance of the economy by their effect on the costs of exchange and production in analyzing the relation between institutional constraints and the amount of forest land converted for use by smallholders this article makes several contributions first it demonstrates that if institutions raise the costs of land conversion then it is possible to utilize an agricultural household model to formalize the resulting impacts on the amount of converted land used by all farming households moreover the equilibrium level of land cleared will differ under conditions of no institutional constraints that is the pure open access situation compared to c onditions where effective institutions exist to control land conversion because institutions raise the cost of land clearing more land should be converted under pure open access 2 this in turn implies that the existence of institutional constraints prevents the adjustment of the stock of converted land to the long run equilibrium desired by agricultural households which is the amount of land that could be cleared under open access a dynamic panel analysis is therefore employed to test the hypothesis that the presence of institutions to control agricultural conversion can significantly affect deforestation the model of land expansion is applied to the case of mexico in the pre nafta north american free trade agreement reform era 1960 85 during this period the existence of ejido or communal land ownership for the vast majority of forest land meant that strong institutional controls may have restricted the rate of adjustment in the amount of new land converted and thus limited agricultural expansion sarukhan and larson 2001 the analysis also has direct relevance for the post nafta period particularly because the 1992 land reforms sanction changes in the traditional ejido land ownership structure ii a pure open access model of forest land conversion the following model of forest conversion is based on an approach similar to that of cropper et al 1999 lopez 1997 1998a and panayotou and sungsuwan 1994 assume that the economic behavior of all j rural smallholder households in the agricultural sector of a developing country can be summarized by the behavior of a representative jth household although the representative household is utility maximizing it is a price taker in both input and output markets farm and off farm labor of the household are assumed to be perfect substitutes such that the opportunity cost of the household s time i e its wage rate is exogenously determined the household s behavior is therefore recursive in the sense that the production decisions are made first and then the consumption decisions singh et al 1986 in any time period t let the profit function of the representative agricultural household s production decisions be defined as 1 max pi p w w

the male marital earnings premium in the context of bride wealth payments evidence from south africa abstract this study explores the nature of the male marital earnings premium in the context of a developing country in which the payment of bride wealth is practiced we use data from the south african labor force survey of september 2004 and the labor force survey panel 2001 4 the first national panel available in south africa we show that a robust and positive premium to marriage in cross sectional estimations is substantially reduced after controlling for individual fixed effects furthermore we find evidence of an additional source of endogeneity created by the positive selection of men into marriage with faster earnings growth in the initial periods of the panel our results are to be expected if the payment of bride wealth or ilobolo by a prospective husband to the bride s family is a significant constraint to marriage among black men in south africa

learning about a new technology pineapple in ghana this paper investigates the role of social learning in the diffusion of a new agri cultural technology in ghana we use unique data on farmers communication patterns to define each individual s information neighborhood conditional on many potentially confounding variables we find evidence that farmers adjust their inputs to align with those of their information neighbors who were surpris ingly successful in previous periods the relationship of these input adjustments to experience further indicates the presence of social learning in addition applying the same method to input choices for another crop of known technol ogy correctly indicates an absence of social learning effects jel d83 013 033 q16

land clearance and social capital in mountain agro ecosystems the case of opuntia scrubland in ayacucho peru abstract opuntia scrublands are important ecological economic systems in rural andean areas they provide goods for peasants diet and animal feed as well as cochineal insects a highly valued source of dyes land clearance on these scrublands promotes changes in land use from nonproductive wilderness to cochineal and fruit harvest areas grazing lands and fuel wood supply zones here we empirically explore the role of social capital on land clearance based on a case study of the humanga region of ayacucho peru the literature on social capital is showing evidence of the positive effect of social capital on development actions and on environmental conservation in rural areas of developing countries such as participatory forest management here the notion of social capital is captured by the idea that some features of social organization such as networks facilitate coordination and cooperation within the peasant communities that help in managing different economic activities both on and off farm the habilitation of the scrublands in the andean mountain environment could be generating negative externalities as a consequence of altering the vegetation cover such as soil erosion because the benefits arising from land clearance activities are obtained by cochineal collecting households and the negative environmental effects are costs imposed upon noncochineal collectors the social capital associated with scrubland habilitation could be perverse from an agro environmental viewpoint and a revision of some government policies and of some ngos actions for rural development through the promotion of various community networks in this deprived area could be needed

the geography of market failure edge effect externalities and the location and production patterns of organic farming abstract perceptions of increasing land scarcity and negative impacts of chemical based agriculture have led to increasing concern regarding the sustainability of food systems incompatible production processes among farming systems may lead to spatial conflicts and production losses between neighboring farms and the magnitude of such losses may depend not only on the scale of each activity but also on patterns of land use such conflicts can be classified as edge effect externalities spatial externalities whose marginal impacts decrease as distance from the border generating the negative impact increases this paper tests the hypothesis that edge effect externalities have influenced the location and production patterns of certified organic farms using data from california central valley certified organic farmers using concepts from landscape ecology and spatial statistics we investigate difference in parcel geometry and surrounding land uses between organic and non organic parcels using a generalized method of moments gmm spatially autoregressive econometric model we demonstrate that both parcel geometry and surrounding land uses influence the probability of a given parcel being certified organic we conclude with suggestions for policies to encourage development of organic farming regions

cross compliance as payment for public goods understanding eu and us agricultural policies cross compliance cc is a mechanism for encouraging farmers to fulfill certain environmental conditions in return for governmental support payments introduced to united states us and european union eu agricultural policy from the 80s onwards upcoming new us farm bill 2012 and eu common agricultural policy after 2013 policies will include cc cross compliance is seen i as a policy for enforcing environmental objectives or ii as a way to organize and reward agricultural public good production in recent years the instrument s effectiveness and efficiency have been criticized to validate the deviating understandings we drew back on an economic institutionalist perspective we found that regarding eu cc as payment for public goods does not generally align with the existing german property rights distribution in both the eu and us cc standards above those contained regulatory law have characteristics of a payment for public goods but create severe problems we conclude that cc even if useful for triggering and broadening environmental protection efforts may cause several long term problems therefore the rights structure should be clearly communicated law enforcement function should be temporary the instrument should be included in an overall concept and payments should be better linked to the environmental output

revisiting the relation between economic growth and the environment a global assessment of deforestation pollution and carbon emission abstract the un s sustainable development goals for 2030 aim on one hand at inclusive growth and eradicating poverty and on the other at preserving environments the relation between development and the environment has been studied extensively since the 1990s documenting inverted u shaped relations between per capita income and indicators of environmental degradation this paper revisits the issue with machine learning techniques and novel disaggregate data to model these relationships heterogeneously across economic indicators results suggest that development gradually improves the efficiency of consuming the earth s nonrenewable resources but increased efficiency alone is not sufficient to offset growth in scale development shifts reliance on one nonrenewable source to another and on average we find successive inverted u shapes in deforestation air pollution and carbon intensities followed by a j shape in per capita carbon output local economic circumstances further determine the shape amplitude and location of tipping points in environmental output the general implications of the estimated dynamics are explored by extrapolating environmental output to 2030 under simplistic scenario s the results are a reminder that immediate and sustained global efforts are required to preserve our environment

the tragedy of the commons in cote d ivoire agriculture empirical evidence and implications for evaluating trade policies expansion of cultivated land diminishes the extent of forestlands or reduces the length of fallow periods and hence reduces the amount of natural vegetation the increase in land under cultivation has a direct output increasing effect at the cost of reducing natural capital and agricultural productivity the evidence for western cote d ivoire is consistent with and provides an explanation for the declining agricultural productivity observed in sub saharan africa during the past few decades this article uses a theoretical model to determine the level of land cultivation that maximizes village income using data from cote d ivoire for 1985 87 an important part of the land is under common property usually at the village level the results show that farmers do not internalize even a small fraction of the external cost of biomass in their land allocation decisions the lack of internalization of the social cost of the biomass resource leads to large income losses at the village level as much as 14 percent of village income these losses are many times larger than the usual estimates for conventional distortions

understanding the family gap in pay for women with children as the gender gap in pay between women and men has been narrowing the family gap in pay between mothers and nonmothers has been widening one reason may be the institutional structure in the united states which has emphasized equal pay and opportunity policies but not family policies in contrast to other countries that have implemented both the authors now have evidence on the links between one such family policy and women s pay recent research suggests that maternity leave coverage by raising women s retention after childbirth also raises women s levels of work experience job tenure and pay

male marital wage differentials training personal characteristics and fixed effects i introduction there is substantial evidence that married white men earn between 8 and 15 more than unmarried white men in the united states even after controlling for education and informal job market experience e g potential or actual experience cross section analysis indicates that both the level and the growth rate of wages increase during marriage these results suggest that men may become more productive after marriage an effect often attributed to the increased specialization possible following the formation of a multiperson household however panel estimates indicate that much of the differential is explained by individual specific fixed effects which suggest that more productive men are more likely to marry while these results and implications are well known the precise nature of the implied productivity differentials has received little attention in the literature using the 1979 cohort of the national longitudinal survey of youth nlsy79 we investigate the structure or source of the observed differential we do so by first extending the analysis to a sample of african american men in the united states to our knowledge ours is the first study to conduct a detailed analysis of the marital wage gap among african american men that is fully comparable to that already available for white men this extension is informative because african american households are known to exhibit less specialization along gender lines and because marital patterns are quite different by race next we explore formal job training as one avenue to productivity enhancement we outline a simple story suggesting that married men may be more receptive to training opportunities than unmarried men and present some evidence suggesting that firms may be more willing to offer training to married as compared to unmarried men previous analysis has focused on labor market experience or years married as proxies for both informal and formal job training we significantly improve upon this by using direct information on formal job training to see if wage changes at or following the time of marriage are driven by training induced productivity differentials third we explore the nature of the selection effect or the possibility that it is more productive men who marry the nlsy79 has an extensive array of information on personal characteristics that might be associated with both marriage and earnings if certain personal characteristics are associated with both marriage and earnings but not typically included in wage analyses then the marital controls in standard wage equations may simply be proxying for these characteristics controlling for such characteristics directly should identify the nature of the selection effect and reduce the significance of the marital indicators in cross section estimates the attributes we examine include cognitive skills parental background and personality traits our final contribution is to estimate panel models to eliminate all observable and unobservable individual specific time invariant factors and to reconcile these results with those obtained from cross section models specifically we exploit the different identification conditions between panel and cross section models examining the role of respondents who are always married never married or always separated divorced technically such individuals contribute to the identification of the cross section but not the panel estimates of the marital wage differential thus these individuals may explain the substantial differences often observed between panel and cross section estimates of the white male marital wage differential ii literature review evidence of the marital wage differential for white men in the united states is extensive see ribar 2004 for a review some of this differential has been attributed to a selection effect to the fact that men who marry earn more throughout their lives than men who do not marry

spatial interactions in multiple use forestry and substitution and wealth effects for the single stand abstract forestry models often ignore spatial relationships between forest stands this paper isolates the effects of stand interactions in multiple use forestry through a straightforward extension of the single stand model effects of stand interactions decompose into wealth and substitution effects and may cause time varying patterns of resource use for a forest stand simulations illustrate that a stand s role even in steady state may alternate an emphasis on timber with an emphasis on nontimber optimal management plans differ substantially depending on whether the manager values nonmarket goods from neighboring stands the model offers insights for improving heuristic forest level optimization models in current usage

coexistence rules and regulations in the european union the institutional environment for planting gm crops in europe is heterogeneous poland wants to ban the planting of gm crops spanish farmers have been growing bt maize for several years 120 communities in belgium have declared themselves to be gmo free a local grain trader in germany has announced that it will pay the same price for bt and non bt maize luxemburg wants to fine farmers up to 750 000 for non compliance with coexistence rules and in poland a prison sentence of up to three years may be given farmers in upper austria must apply for authorization for each field intended to be planted with gm crops and farmers in denmark have to pay a levy of 100 dk per hectare of gm crops in 2003 the european commission stated that no form of agriculture be it conventional organic or agriculture using genetically modified organism gmos should be excluded in the european union but simultaneously decided to follow the principle of subsidiary that measures for coexistence should be developed and implemented by the member states cec 2003a p 1 since then some member states have developed and others are still developing a diversity of coexistence measures that may have a profound impact on the adoption rate of gm crops against this background we ask the following question how will the different coexistence policies among eu member states affect the adoption of gm crops

environmental externalities in traditional agriculture and the impact of trade liberalization the case of ghana abstract this paper provides a framework for the evaluation of trade policies that explicitly considers the effects of such policies on the environmental resources biomass in doing this we estimate the effects of biomass as a factor of agricultural production and test the hypothesis that farmers efficiently exploit biomass a resource held in common property the main findings are i biomass is an important factor of production in ghanian agriculture ii the biomass resource is exploited beyond the socially optimal level iii a deepening of trade liberalization is likely to induce further losses of biomass and deforestation and iv national income is likely to fall in response to further trade liberalization

an optimal path to extinction poverty and resource degradation in the open agrarian economy this paper constructs a model of the open agrarian economy in order to explore the tendency of many such economies to evolve along paths characterised by severe environmental degradation it pays special attention to the importance of commodity prices and the transfer system in determining agricultural activity levels in ecologically delicate systems

links between economic liberalization and rural resource degradation in the developing regions this paper examines evidence of the effects of economic liberalization and globalization on rural resource degradation in developing countries the principal resource effects of concern are processes of land use change leading to forestland conversion degradation and deforestation the main trends in globalization of interest are trade liberalization and economy wide reforms in developing countries that have opened up the agroindustrial sectors thus increasing their export orientation such reforms have clearly spurred agroindustrialization rural development and economic growth but there is also concern that there may be direct and indirect impacts on rural resource degradation the direct impacts may occur as increased agricultural activity leads to conversion of forests and increased land degradation from unsustainable production methods however there may also be indirect effects if agroindustrial development displaces landless near landless and rural poor generally who then migrate to marginal agricultural lands and forest frontier regions this paper explores these direct and indirect effects of globalization and agroindustrialization on rural resource degradation both generally plus through examining case study evidence the paper focuses in particular on the examples of structural adjustment trade liberalization and agricultural development in ghana and maize sector liberalization in mexico under north american free trade agreement nafta

agri environmental policy and urban development patterns a general equilibrium analysis this paper investigates the spatial effects that the provision of environmental public goods have on residential location choices in a suburban context specifically a spatial general equilibrium framework is developed to analyze the consequences of adopting an agri environmental policy promoting the provision of positive farming externalities we use a static monocentric model of an open city where agricultural bid rents and agricultural amenities vary endogenously in space and where the positive externalities associated with agricultural production are valued by households consistent with empirical evidence of the potential side effects that conservation policies may have in terms of urbanization patterns and land price changes we show that under certain conditions implementing an agri environmental policy may promote additional suburban development moreover we demonstrate that the emergence of disconnected suburban areas may be significantly influenced by the location of land regulated by an agri environmental policy finally we discuss distributional aspects and show that while introducing an agri environmental policy has a negative impact on most residential land value it can have positive effects on farmland and residential land located within the regulated areas suggesting the non neutrality of such policies regarding the agents assets

on the evidence of a working spouse penalty in the managerial labor market this analysis of march 1993 current population survey data suggests that managers with working wives earn lower wages than their counterparts with non working wives the labor supply decisions of managers wives appear to be unaffected by that is exogenous with respect to their husbands wages in contrast there is evidence that the labor supply decisions of non managers wives are affected by their husbands wages and when the analysis takes account of that endogeneity it is found that non managers do not suffer a working spouse penalty the analysis also highlights some important issues related to the use of instrumental variables

learning by doing and learning from others human capital and technical change in agriculture household level panel data from a nationally representative sample of rural indian households describing the adoption and profitability of high yielding seed varieties hyvs associated with the green revolution are used to test the implications of a model incorporating learning by doing and learning spillovers the estimates indicate that i imperfect knowledge about the management of the new seeds was a significant barrier to adoption ii this barrier diminished as farmer experience with the new technologies increased iii own experience and neighbors experience with hyvs significantly increased hyv profitability and iv farmers do not fully incorporate the village returns to learning in making adoption decisions

bayesian spatial probit estimation a primer and an application to hyv rice adoption increasingly spatial econometric methods are becoming part of the standard toolkit of applied researchers in agricultural environmental and development economics nonetheless applications in discrete choice settings remain few and despite its appeal applications of the bayesian paradigm in these settings are still fewer we provide a primer to the bayesian spatial probit with the objective of making accessible to non users a class of iterative estimation methods that have become fairly routine in bayesian circles offer an extremely powerful addition to applied researchers toolkits and are essential in bayesian implementation of spatial econometric models we demonstrate the methods and apply them to estimate the neighbourhood effect in high yielding variety hyv adoption among bangladeshi rice producers we estimate the strength of this relationship using a standard spatial probit model and compare the policy conclusions with and without the neighbourhood effect included

do migrants really save more understanding the impact of remittances on savings in rural china abstract this article studies the impact of remittances on the savings behaviour of rural households in china using a primary survey undertaken by the authors in 2006 allowing for endogeneity and left censoring of remittances we find that the marginal propensity to save out of remittances is well below half of that out of other sources of incomes moreover we find no evidence of any direct effect of remittances on either capital input or gross output of farm production these findings are robust with respect to alternative definition of savings and are in line with recent studies which conclude that remittances are largely used for consumption purposes by rural chinese households

globalization local ecosystems and the rural poor summary in this paper we draw upon models from ecology and new institutional economics to examine the various mechanisms through which globalization can lead to loss in resilience of ecosystems and thus increase the vulnerability of poor people who depend on it to illustrate ecological dynamics we examine a semi arid savanna ecosystem that is characterized by nonlinearities and multiple steady states we discuss how traditional knowledge and institutions affect resource use patterns and resilience of such an ecosystem in the absence of trade then we examine the effects of trade liberalization and international technology transfers on institutional and ecological dynamics and consequently on poverty

pricing and regulating affect environmental ethics effluent charges and tradeable permits are economically efficient but rarely used a new explanation for this discrepancy is offered pricing may crowd out environmental ethics in the pricing and via spillovers also in non pricing sectors pricing may therefore increase pollution providing a reason why decision makers tend to reject environmental pricing five propositions showing the conditions for counterproductive effects are advanced they are consistent with available empirical evidence regulation by setting standards and subsidies damage environmental ethics less than pricing because pollution is condoned damaging environmental ethics may prevent political action in favor of the environment

interactive dynamics between natural and man made assets the impact of external shocks abstract this paper studies a two sector economy in which one of the sectors the commodity sector depends in part on the exploitation of a renewable natural resource and examines the issue in an economy wide context where both natural resources and a man made asset change endogenously over time we show that under an open access resource regime i a resource rich capital poor economy may experience a natural resource curse phase and under certain conditions may even follow a non sustainable path leading to complete natural resource depletion ii a labor inflow results in a higher steady state per capita income with unchanged natural resources though it makes the economy more prone to reach a path that converges to resource collapse iii the introduction of a small import tariff or export tax results in larger steady state natural resources and commodity output and renders the economy less vulnerable to resource collapse we also contrast the open access case with the other polar case of perfect property rights showing that in this case the economy experiences neither a resource curse nor a resource collapse

temporal and spatial modelling of tropical deforestation a survival analysis linking satellite and household survey data we estimate a spatially explicit model of the forest clearance process among smallholder farmers in an agricultural frontier of southern mexico our analysis takes as its point of departure a simple utility maximising model that suggests many possible determinants of deforestation in an economic environment characterised by missing or thin markets hypotheses from the model are tested on a data set that combines a time series of satellite imagery with data collected from a survey of farm households whose agricultural plots were geo referenced using a global positioning system gps we implement a survival analysis to identify the effect of household level explanatory variables on the probability of deforestation this approach allows us to introduce a measure of the time until clearance as a covariate thereby affording a control for the effect of potentially important explanatory variables that vary through time but are not directly observable in addition to identifying several variables relevant for policy analysis including household demographics proximity to roads and government provision of agricultural support model results suggest that the deforestation process is characterised by non linear duration dependence with the probability of forest clearance first decreasing and then increasing with the passage of time

spatial externalities in agriculture empirical analysis statistical identification and policy implications summary spatial externalities can affect economic welfare and landscape pattern by linking farm returns on adjoining parcels of land while policy can be informed by research that documents spatial externalities statistically quantifying the presence of externalities from landscape pattern is insufficient for policy guidance unless the underlying cause of the externality can be identified as positive or negative this article provides a springboard for empirical research by examining the underlying structure social environmental interactions and statistical identification strategies for the analysis and the quantification of agricultural spatial externalities that are derived from observations of landscape change the potential for original policy treatments of agricultural spatial externalities in development and environment outcomes is highlighted

the tragedy of the commons in cote d lvoire agriculture expansion of cultivated land diminishes the extent of forestlands or reduces the length of fallow periods and hence reduces the amount of natural vegetation the increase in land under cultivation has a direct output increasing effect at the cost of reducing natural capital and agricultural productivity the evidence for western cote d lvoire is consistent with and provides an explanation for the declining agricultural productivity observed in sub saharan africa during the past few decades this article uses a theoretical model to determine the level of land cultivation that maximizes village income using data from cote d lvoire for 1985 87 an important part of the land is under common property usually at the village level the results show that farmers do not internalize even a small fraction of the external cost of biomass in their land allocation decisions the lack of internalization of the social cost of the biomass resource leads to large income losses at the village level as much as 14 perce

market crashes and informational avalanches this paper analyses a security market with transaction costs and a sequential trading structure transaction costs may prevent many traders from revealing their private information if they trade in a sequential fashion due to the information aggregation failure hidden information gets accumulated in the market which may be revealed by a small trigger yielding a high volatility in the absence of an accompanying event the paper first characterizes the optimal trading strategy of the agent which constitute the unique equilibrium further properties of the price sequence are obtained using the concepts of informational cascade and informational avalanche the results are applied to the explanation of market crashes in particular the dynamics of market crashes are illustrated as evolving through the following four phases 1 boom 2 euphoria 3 trigger and 4 panic where the euphoria corresponds to the informational cascade and the panic corresponds to the informational avalanche

capturing household level spatial influence in agricultural management using random effects regression abstract data on agricultural and natural resource management typically have spatial patterns related to the landscapes from which they came consequently econometric models designed to explain the determinants of humans natural resource management practices or their outcomes often have spatial structure that can bring bias or inefficiency to parameter estimates although econometric tools are available to correct for spatial structure such tools are largely lacking for use with discrete dependent variable models while one obvious solution would be to develop the necessary tools an alternative is to identify conditions under which spatial dependency can be managed effectively without formal spatial autoregressive models this study examines conditions under which spatial structure corresponds closely to defined agro ecological zones making it possible to model spatial effects by random effects regression using household survey data sampled along agro ecological zone strata this article develops two models of links between farmer assets and agricultural natural resource degradation in southern peru the first stage model looks at determinants of crop yield loss over time an index of soil productivity while the second stage model looks at determinants of the extent of fallow cycles in crop rotation a key agricultural practice reducing crop yield loss diagnostic statistics for spatial dependency reveal spatial structure particularly in the fallow model this spatial dependency is eliminated in the ordinary least squares ols models by inclusion of the agro ecological zone random effects in the spatially dependent fallow model comparison of coefficient estimates between ols and the spatial autoregressive maximum likelihood models showed ols with random effects to give virtually identical results to the spatial autoregressive models making the latter unnecessary these results show that spatial structure in natural resource management models can sometimes be captured by zonal variables when this occurs random effects regression can largely eliminate spatial dependency a necessary precondition for this approach with household survey data is prior sample stratification according to landscape characteristics where random effects models can effectively capture spatial structure they may also offer analysts greater flexibility in analyzing models with limited dependent variables

the social costs of second best policies evidence from agricultural ghg mitigation abstract this paper investigates the social costs of second best agricultural greenhouse gas ghg mitigation policies adjustments along the land use and input intensity margins are represented within a regionalized optimization model of california crop production calibrated to economic and agronomic information second best policies relying on spatially aggregated ghg emission factors lead to small abatement efficiency losses while policies targeting a single ghg lead to moderate losses in contrast policies targeting a single input entail large abatement efficiency losses which nonetheless can be reduced by combining instruments

considering the effect of biomass energy consumption on economic growth fresh evidence from brics region abstract this paper investigates the relationship between biomass energy consumption and economic growth by incorporating capital and trade openness in production function for the case of brics countries in doing so unit root and cointegration tests have been used in order to examine unit root properties and long run relationship between the series for the period of 1991q1 2015q4 the results confirm the presence of long run equilibrium relationship between the variables moreover biomass energy consumption stimulates economic growth capital increments economic growth and trade openness spurs economic growth the feedback effect exists between biomass energy consumption and economic growth trade openness granger causes economic growth capital and biomass energy consumption the policy to adopt biomass as the primary source of renewable energy helps brics countries to achieve sustainable development goal in both short run and long run however the key innovative point of this study is to establish the sign for granger causality test

national accounts and environmental resources in the paper optimal growth theory is used to derive the appropriate definition of the net national product concept when there are environmental resources and environmental damage to take into account the basic conclusions are that conventional defined np should be corrected by deducting environmental damage and adding the value of the net change of all resources

an institutional analysis of payments for environmental services abstract in this paper the characteristics and functioning of pes is analyzed from an institutional perspective while in theory pes is seen as a market solution to environmental problems as an alternative to state hierarchical and community governance a review of a large amount of case studies shows that pes in practice depends rather fundamentally on state and or community engagement hence pes are foremost a reconfiguration of the roles of public bodies and communities becoming core intermediaries or buyers first to establish pes rights to the land that delivers the environmental service must be clarified this demands public action second transacting over environmental amenities is very costly creating markets for environmental services depends therefore crucially on state and community facilitation hence buyers are often public agencies high transaction costs also influence price setting payments do not follow the market format as intermediaries frequently are setting the price with users often being unaware even of the fact that they pay finally the distinction between payments as incentives and as fair compensations is emphasized while payments may strengthen community relations and simplify action for environmental care they may also introduce a purely instrumental logic and in some cases worsen the environmental status by crowding out environmental virtues for the future greater awareness of these dynamics is warranted

discrete choice with social interactions this paper provides an analysis of aggregate behavioural outcomes when individual utility exhibits social interaction effects we study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behaviour of others in an environment of noncooperative decisionmaking laws of large numbers are generated in such environments multiplicity of equilibria in these models which are equivalent to the existence of multiple self consistent means for average choice behaviour will exist when the social interactions exceed a particular threshold local stability of these multiple equilibria is also studied the properties of the noncooperative economy are contrasted with the properties of an economy in which a social planner determines the set of individual choices finally a likelihood function based on the theoretical model is given and conditions for the econometric identifiability of the model are established

the effects of government spending on deforestation due to agricultural land expansion and co2 related emissions this paper examines the effect of changes in government spending level and composition on deforestation due to agricultural land expansion and related carbon dioxide emissions our theoretical model shows an unintended consequence from increased government spending and widening social safety nets in developing countries where agricultural land expansion significantly affects forest cover there is an increase in deforestation and carbon dioxide emissions from land use change our empirical tests show that an increase in total government spending significantly increases forest land clearing for agricultural production in the short run leading to more carbon dioxide emissions however there is no long run statistically significant effect on the steady state forest cover and carbon dioxide emissions

making the commons work conservation and cooperation in ireland commonage represents land held under common property that incorporates a system of local cooperative arrangements and rules to conserve and manage the irish uplands we analyze the institutional and economic factors that influence the behavior of commonage farmers under a common property regime using a recursive bivariate probit model results show that 1 cooperation has a positive and important impact on commonage conservation 2 agricultural policies by way of livestock premia increase the level of degradation while 3 farm financial support through agrienvironment measures positively affects commonage conservation and encourages cooperation between farmers

agricultural productivity and soil carbon dynamics a bioeconomic model we examine the dynamic management of a soil resource the issue at the core of both environmental and development challenges in developing countries our theoretical framework extends the traditional bioeconomic model of renewable resources to soil carbon management and investigates the effects of changes in agricultural practices on farmers natural resource base and livelihoods we parameterize the model using an eight year panel data set from an agronomic experiment and data from household and market surveys in the western kenyan highlands the optimal maize yields and soil carbon stocks are higher than those observed in the region this divergence is partly explained by farmers heterogeneous time preferences with the implied discount rates of 5 to 25 information barriers and market imperfections the steady state shadow price for soil carbon ranges from 95 mg to 168 mg indicating a significant opportunity cost for soil mismanagement

measuring regional diversification of environmental externalities in agriculture and the effectiveness of their reduction by eu agri environmental programs in poland abstract the problem of externalities is an important aspect of contemporary discussion about the directions of agricultural development and agricultural policy nonetheless measuring agri environmental externalities is a difficult task and rarely undertaken in scientific research in our research we have constructed a synthetic indicator that allows measuring agri environmental externalities at the regional level taking into account both positive and negative effects at the same time we also studied the extent to which our synthetic indicator can be used to inform about the effectiveness of subsidies paid to farmers in the european union under agri environmental programs in reduction of externalities generated by agriculture we concluded that the use of subsidies under agri environmental programs has a positive impact on reducing externalities generated by agricultural production measured by our indicator

work contracts and earnings inequality the case of chile great social inequality has been one of the worrisome features of economic development in latin america this study focuses on chile one of latin america s fastest growing economies with one of the highest levels of income inequality during the 1990s using micro level data from the 1994 and 2000 encuestas de caracterizacion socio economica this article examines the role of work contracts in explaining male and female earnings and earnings inequality among wage and salary workers over the second half of the 1990s the analysis distinguishes between wage and salary work without a work contract referred to as informal work and wage and salary work with a work contract within the latter group the study further differentiates by the type of work contract held such as permanent and a variety of contingent work contracts the findings reveal that the majority of employees in informal and contingent wage and salary work arrangements earned significantly less than their permanent counterparts additiona

on levies to reduce the nitrogen surplus the case of dutch pig farms pig farms in the netherlands pay a zero or low price for using the environment as a consequence the environment is overused the dutch government wants to reduce the emissions of nitrogen and phosphorus possible instruments are regulation and levies in this study a levy on feed and a levy on the nitrogen surplus are investigated by incorporating a bad output in the production model the model is estimated using panel data of dutch pig farms over the period 1975 1989 levies on nitrogen turn out to be more cost effective than levies on feed

should governments stop subsidies to private goods evidence from rural latin america abstract this paper empirically documents the effects of subsidizing private goods to the detriment of the government s supply of public goods we use a new data set from the rural sector in fifteen latin american countries over the period 1985 2001 collected using a methodology that allows us to separate government subsidies to private goods from expenditures in the provision of public goods the econometric evidence shows that the government s decision to subsidize either private or public goods has dramatic consequences for economic development reducing the share of subsidies to private goods or equivalently increasing the share of public goods in the government s budget has ceteris paribus a large and significant positive impact on rural per capita income reduces certain undesirable environmental effects associated with output expansion and contributes to poverty reduction

why do married men earn more productivity or marriage selection injae lee using data from the current population survey march supplement 1999 this study examines why married men earn more than men who have never married we find that the marriage wage premium cannot be attributed to the unobservable higher earnings capability of married men instead wage gains from marriage are explained by the degree of specialization within the household our findings cast doubt on the argument that the selection of high ability men into marriage is the cause of the marriage wage premium jel j12 j31 i introduction labor economists have devoted considerable effort to explaining why married men earn higher wages than men who have never married a number of theoretical hypotheses have been advanced to explore the nature of this marriage wage premium the dominant theory is the productivity hypothesis which argues that marriage makes men more productive becker 1991 married men have greater opportunities to specialize in labor market activities when their wives specialize in home production the marriage wage premium reflects a productivity gap between married and never married men stemming from different conditions for human capital accumulation in market work a competing argument is the selection hypothesis nakosteen and zimmer 1987 1997 this reverses the direction of causality proposing that men with a higher earnings capability are valued more in the marriage market and are thus more likely to marry the marriage premium mirrors the marriage selection pattern married men are more productive not because they become more productive after marriage but because they were more productive before marriage 1 while there is compelling evidence that married men have higher earnings than never married men hill 1979 the relative merits of the productivity and selection arguments in explaining the existence of the marriage premium remain to be established nakosteen and zimmer 1987 argue that the marriage premium is a statistical artifact arising from a sorting process in which high wage males tend to be selected into marriage when selection effects are accounted for in their wage regression the marriage premium remains numerically large but becomes statistically insignificant however korenman and neumark 1991 show that the selection hypothesis is an incomplete explanation of the marriage premium they find that less than one half of the marriage premium vanishes when unobservable individual factors affecting both wages and marriage are removed the remaining premium is interpreted as the productivity enhancing effects of marriage later studies examine the validity of the productivity explanation using measures for the household division of labor such as a wife s labor market hours and the number of children in the household the studies investigate the effects of household specialization on a husband s earnings according to the productivity hypothesis men whose wives specialize in home production should have a larger premium than men whose wives work in the labor market the evidence for this is mixed daniel 1992 and gray 1997 find that the marriage premium is negatively associated with the wife s labor market hours whereas loh 1996 and jacobsen and rayack 1996 find little evidence that the marriage premium is explained by productivity differences past work tries to clarify the relationship between marriage household specialization and a husband s earnings but it does not allow us to reach an empirical consensus about the cause of the marriage premium in this article we present a new empirical framework to test the relative merits of two competing but not mutually exclusive hypotheses first we develop a switching regression model with endogenous marriage selection the selection hypothesis is founded on the premise that a man s attractiveness as a potential mate depends upon his observed earnings as well as unobservable individual traits that are positively related to his earnings potential

peasants against private property rights a review of the literature land is the main if not the only asset for a majority of people in developing countries the definition and allocation of rights over land are thus naturally essential aspects of individuals daily lives as well as critical determinants of social and economic development the privatization of land rights has long been seen as a necessary process enhancing both efficiency and equity however privatized land rights have not always emerged endogenously while exogenously driven programs of land privatization have not always been successful nor popular this has raised questions about the expected benefits of land rights privatization this paper aims at summarizing the main arguments and studies both theoretical and empirical on this issue with a specific focus on the factors that can make privatization inefficient or detrimental for the most concerned individuals

marital status and productivity evidence from personnel data although a robust wage premium for married men has been documented extensively in the labor economics literature prior studies have been hampered in testing competing explanations of the premium by a lack of data on worker productivity this study exploits a unique data set that contains job performance measures for employees of a large hierarchical organization the quasi longitudinal data track the marital status and job productivity including performance reviews and promotions of male naval officers in technical and managerial jobs compared with single men married men receive significantly higher performance ratings and are more likely to be promoted in estimates that control for selection arising from quit decisions the size of the marriage productivity effect falls but in most cases remains robust also based on supplementary tests selectivity arising from the decision to marry appears to explain only a small portion of the unadjusted marriage premium for navy officers although the existence of a wage premium for married men has been documented extensively in the labor economics literature the source of the premium has remained controversial one hypothesis attributes the wage differential to economies of scale and specialization within the household which provides incentives for additional investment in specific human capital by married men becker 1981 alternative hypotheses are that the marriage premium stems from employer favoritism or that more productive or higher earning men are selected into marriage the extensive empirical literature that has attempted to test the competing explanations has produced conflicting conclusions however one research approach to assess the effect of marital status that seldom has been implemented in the prior literature is to use data on the realized productivity of employees of a single firm this study uses administrative data on male employees of a large hierarchical organization to explore the effect of marital status on selected job performance measures the personnel database covers male u s naval officers and contains relatively detailed information on career performance including promotion outcomes and annual performance reviews the article seeks to shed light on the existence and magnitude of job productivity differentials between married and single males and to assess competing explanations for marriage related performance differentials navy personnel data are especially fertile for analyzing the effect of marital status on employee job productivity several performance measures are available for each individual and the indicators capture performance throughout an employee s tenure rather than at a single career point the design

do men whose wives work really earn less it is common knowledge among empirical labor economists that household status variables can enter significantly in wage equations in particular a substantial marital wage premium for men has been noted recently a series of articles in the management literature has argued that an even larger premium accrues to those married men whose wives do not work for pay single earner husbands our current study arises in response to perceived deficiencies in the conceptual framework and statistical methods used in these studies

market created risk we develop a multiperiod rational expectations model of securities market equilibrium in which equilibrium prices may move between periods even though it is common knowledge that no new information has arrived about ultimate security payoffs this happens because investors know they have imperfect information about the endowments of other investors and this knowledge affects their probability beliefs about the prices that will prevail at the intermediate trading date these beliefs are reflected in the equilibrium at the initial trading date when investors focus on the probabilities of intermediate capital gains and losses rather than ultimate payoffs virtually all models of the pricing of securities employ some notion of market equilibrium so for prices to fluctuate something in the equilibrium must change since equilibrium in an informationally efficient market implies that market clearing prices reflect all available information about future securities payoffs it seems to be frequently assumed that observed jumps in prices ought under the efficient market hypothesis to reflect the arrival of new information about future cash payoffs to securities the major theme of this paper is to examine a multiperiod model of securities market equilibrium in which equilibrium prices may change sharply between periods even if it is common knowledge that no new information about ultimate payoffs has arrived and all investors are rational and make full use of all available information in our model the new information that leads to a price change is information about how much of the known total supply of risky securities is held by investors of different preferences for this model to produce intertemporal price fluctuation in equilibrium two phenomena must occur firstly the initially unknown composition of the market must not be revealed by equilibrium prices at the initial trading date secondly despite this the true composition of the market must at least partially determine prices at a later trading date they key to both these phenomena lies in the difference in investor behavior when they anticipate revising their current portfolio holdings in response to future price changes as compared to when they choose portfolios on the basis of receiving the ultimate cash payoffs to the securities they buy in practice few investors anticipating holding financial securities to their eventual liquidation by the issuer short term debt or debt close to maturity would be the major exception few equity securities relative to the total supply

dual economic growth in poor tropical areas abstract we consider a two sector model a modern sector and an extensive one with the extensive sector being highly dependent on natural vegetation cover as a factor of production in the extensive sector land tenure is not well defined we show that taxing the extensive sector as a whole and land intensive crops relative to labor intensive crops increases real income consumption in the short run however necessarily falls the cost of the adjustment is paid mostly by the poor when the extensive sector as a whole is taxed the distributional consequences of taxing the land intensive outputs however are ambiguous

agricultural intensification common property resources and the farm household this paper evaluates the impact of agricultural price and intensification policies for common property resources and welfare of rural communities in developing countries in doing so we develop a new model for the farm household that has analytical advantages over the traditional one and that has significant potential for empirical application the major findings are technical assistance that increase productivity of land intensive agricultural outputs cereals livestock etc cause degradation of the communal resources and may cause immiserization policies that increase the prices of these goods cause identical effects by contrast similar policies applied to labor intensive outputs vegetables tubers etc contribute to improve the common resources and to increase the welfare of the rural communities

trade policies economic growth and the direct causes of deforestation by ramon lopez gregmar i galinato please send correspondence to ramon lopez 2200 symons hall university of maryland college park md 20742 email rlopez arec umd edu tel 301 405 1281 fax 301 314 9091 gregmar i galinato 2200 symons hall university of maryland college park md 20742 email ggalinato arec umd edu tel 301 405 0477 fax 301 314 9091

coexistence of gm and non gm crops with endogenously determined separation the possibility that genetically modified gm crops may contaminate non gm crops through pollen mediated gene flow presents a challenge to coexistence of gm agriculture with conventional and organic farming systems in this paper an analytical model of coexistence is developed that allows for endogenous derivation of efficient widths and allocation of pollen barriers to limit contamination of non gm crops to reflect the uncertainty that surrounds pollen dispersal mechanisms the model contains a stochastic contamination function and safety rule decision mechanism constraining the level of contamination to remain below a tolerated adventitious presence with a given probability two policies are considered and their performance is tested the tolerance level of adventitious presence and the allocation of responsibility for implementing coexistence measures to either gm or non gm farmers the relative size of gm rents the value of productivity gains and the non pecuniary benefits from gm crops rents for identity preserved non gm crops price premiums realised over the gm crop price characteristics of farms and possible variation in agricultural landscapes are also taken into account the findings indicate that conventional adventitious presence tolerances can be met without ex ante mandating large widths of pollen barriers at the policy level the findings of this paper are relevant for setting region specific pollen barriers widths and or for establishing institutions that facilitate cooperative coexistence

on price liberalization poverty and shifting cultivation an example from mexico a bioeconomic model is used to explore the potential impacts of price policies on land use under shifting cultivation the model is calibrated with household level and agroecological data from yucatan mexico besides the direct effect of the liberalization of maize prices the results indicate that changes in real wages in post nafta mexico may have non expected effects on the labor diversification and land use decisions of households further it is shown that income may well be inversely related to both the suboptimal level of forest clearing and the state of soil fertility albeit in a non monotonic u shape way

virtual land use and agricultural trade estimating environmental and socio economic impacts abstract liberalization has caused an increase in the global trade of goods and services in particular the value and physical volume of agricultural goods traded have largely increased as the environmental and social consequences of trade are complex they are rarely included in the national and international agricultural policies one reason is that there is a lack of concepts and methods for assessing the environmental and social impacts of trade policies in this paper we develop a method for quantifying and assessing the land use hidden in the export and import of agricultural goods for the case of switzerland for our analysis we focus on arable crops the first methodological step of our research illustrates the spatial relationship of switzerland with countries all over the world through the import and export of land use for arable crops the second step links this spatial dimension with a qualitative assessment of the environmental and socio economic impacts of agricultural land use we applied the method to the case of wheat cultivation within switzerland and import to switzerland the major problem we were confronted with was the availability of data which had both to be reliable and available for the countries wheat is imported from the results show that the calculation of land use is credible in spite of the problems related with data availability the assessment results for each indicator are in agreement with the current situation in the respective countries in addition the aggregation seems to accurately reflect the countries agricultural polices the developed method is used to estimate the overall environmental and socio economic impacts of an increase in wheat imports to switzerland we argue that this method could be applied for anticipating potential impacts of trade agreements still further research is required for fine tuning of the utility functions including a weighting procedure in the aggregation procedure for practical applications important aspects like water shortage should enlarge our limited set of indicators in addition the average impact on a country level was assessed to refine that different agricultural systems ranging from intensive to extensive to organic should be considered beyond our scope was to analyze impacts due to other life cycle stages than the agricultural production for informed decision however information on the whole life cycle of agricultural products is required

external effects of agricultural production in italy and environmental accounting this paper deals with the valuation of some negative external effects arising from agricultural production in italy external effects are treated in a transformation function as a bad output additional to the normal output of a production activity in this case we can distinguish a price component or shadow price of the external effect and a quantity component and estimate them separately in order to calculate the price component of the external effects we first estimate one point on the marginal external costs curve and then try to obtain the whole curve i e external costs associated to different levels of emissions in different years as to the quantity component net emissions of nitrogen phosphorus and potassium have been estimated the aggregate value of external effects is then calculated for thirty years from 1961 to 1991 and deducted from the value added of the agricultural sector as a first step towards the correction of national accounting aggregates to take environmental degradation into account

property rights regimes and natural resources a conceptual analysis the term common property resource is an example of a term repeatedly used to refer to property owned by a government or by no one it is also used for property owned by a community of resource users such usage leads to confusion in scientific study and policy analysis in this paper we develop a conceptual schema for arraying property rights regimes that distinguishes among diverse bundles of rights ranging from authorized user to claimant to proprietor and to owner we apply this conceptual schema to analyze findings from a variety of empirical settings including the maine lobster industry

pigs in space modeling the spatial structure of hog production in traditional and nontraditional production regions we posit a spatially explicit county level model of the hog production sector and estimate how numerous firm specific locality specific and spatial agglomeration factors affect the location movement and intensity of hog production within 15 key hog production states spatial agglomeration urban encroachment input availability firm productivity local economy slaughter access and regulatory stringency variables affect the sample regions spatial organization analyses suggest that western states in the sample may shape hog production levels by wielding traditional business recruitment and retention tools e g tax rates environmental stringency while corn belt states may shape hog production via nontraditional tools e g land use controls few sectors have undergone more rapid change in scale structure and organization than the u s swine sector in the past two decades movement to large scale specialized production units reflects past trends in western cattle feeding and dairy enterprises while increasing vertical coordination resembles patterns adopted in the poultry sector several decades ago accompanying these changes in production has been a simultaneous change in the spatial organization of u s hog production industry analysts have forwarded several stylized facts of this spatial reorganization traditional corn belt states have lost in terms of national share of hog production to southeastern great plains and mountain states during the 1980s and 1990s drabenstott hurt as the firms offering swine production and marketing contracts attempt to locate large scale facilities where there are few people cheap land

debt poverty and resource management in a rural smallholder economy this paper develops a model to capture the key features of poverty credit constraints and resource management faced by poor rural households we assume that due to the existence of asymmetric information and moral hazard the household faces an increasing cost of credit as its debt equity ratio rises a household exploiting a natural resource may fall into a poverty trap but only if it is unable to afford the increasing borrowing costs implied by increasing debt to allow it to avoid such a trap or if it discounts future utility so much that a balanced growth path cannot be financed at any level of long run borrowing in contrast along an optimal balanced growth path the household s asset wealth purchased inputs resource stock and consumption increase at the same constant rate however over the long run there may be carrying capacity limits that prevent the resource from improving further the household may then direct its savings to accumulating financial assets and eventually under certain conditions may become a net creditor with resource exploitation becoming a less and less important source of its income

the policy roots of socioeconomic stagnation and environmental implosion latin america 1950 2000 abstract the persistence of growth and its equity and environmental effects heavily depend on the composition of asset investments physical human and natural capital are the key assets behind the development process market failures tend to affect the accumulation of such assets asymmetrically leading to underinvestment in human and natural capital public policy in latin america has generally exacerbated such market failures by promoting physical capital investments using massive public subsidies instead of relying on the expansion of public and semipublic assets that complement physical capital the result economic stagnation deep social inequities and environmental destruction

deforestation property rights and international trade deforestation primarily affects developing countries most developing countries share two characteristics 1 trade liberalization reforms in the last two decades and 2 weak property rights and limited rule of law this paper investigates this second best world first in a stylized model in which trade distortions are eliminated in an economy whose natural resources are subject to open access second empirically in an estimation exercise that disentangles the direct effect of trade on deforestation rates and an indirect effect through its interaction with ownership security in accordance with the theory the results show that only the indirect effect is significant

marriage and wages a test of the specialization hypothesis we investigate the relationship between marriage and wages among men in britain using panel data our econometric specifications allow for observed and unobserved heterogeneity and explicitly test the role of intra household specialization in explaining the observed relationship our estimates provide evidence for the existence of large selection effects into marriage based on observable and unobservable characteristics that are positively correlated with wages after accounting for individual specific time invariant effects and a wide range of individual household job and employer related characteristics we find a statistically significant premium that can be attributed to productivity differences largely resulting from intra household specialization

deprived land use intensification in shifting cultivation the population pressure hypothesis revisited this article provides a theoretical framework based on optimal control theory to analyze farm households land use intensification decisions in forest based shifting cultivation slash and burn agroecosystems the main results from the analysis generally coincide with the population pressure hypothesis pph as an important driver of soil degradation due to the so called fallow crisis or deprived land use intensification in shifting cultivation however the model also shows from a supply perspective that such a vicious circle of lower yields and greater forest land clearing may be avoided when the production elasticity of on farm labor outweighs the elasticity of substitution between farm labor and soil fertility furthermore using data from shifting cultivating households from yucatan mexico we calibrate the effect of changes in population density the numerical analysis suggests that by contrast to better off households when population density increases poorer shifting cultivating households optimal labor allocation strategy is to further extensify land use by clearing more forest in the village common property land or ejido land

self organization and market crashes this paper presents a model of stock price behavior that encompasses both short term fluctuations and long term exponential trends punctuated by crashes the model represents stock market behavior as the interaction of two self organizing processes the first process represents business as usual stock price fluctuations it builds on a model of stock price behavior introduced by cont and bouchaud the second process is a risk process that determines the severity of crashes it is a random graph process driven by macroeconomic variables our model is based on the assumption that stock market prices that grow at a higher rate than the real economy force structural changes that in turn leverage the risk of a crash the transition from a business as usual regime to a crash regime is determined by trigger events trigger events are exponentially distributed while the size of a crash depends on the state of the underlying risk process while in the short term the performance of stock prices may be determined by the purely speculative behavior of agents the long term behavior of stock prices is essentially a function of structural and macroeconomic parameters

agricultural policies and trade paths in turkey in 1959 shortly after the european economic community was founded under the 1957 treaty of rome turkey applied for associate membership in the then six member common market by 1963 a path for integrating the economies of turkey and the eventual european union had been mapped as with many trade agreements agriculture posed difficult political hurdles which were never fully cleared even as trade barriers to other sectors were eventually removed and a customs union formed this essay traces the influences the turkey european union economic institutions have had on agricultural policies and the agriculture sector an applied general equilibrium framework is used to provide estimates of what including agriculture under the customs union would mean for the sector and the economy the paper also discusses the implications of fully aligning turkey s agricultural policies with the european union s common agricultural policy as would be required under full membership

a microscopic model of the stock market cycles booms and crashes abstract we present a model of the stock market based on the behavior of individual investors simulations exhibit rich phenomena which include cycles booms and crashes low dividend yield and more homogeneous market participants are shown to induce crashes

a model of shifting cultivation can soil conservation reduce deforestation shifting cultivators manage soil not only by adjusting soil use on already cleared lands as in continuous cultivation but also by clearing forests to obtain new fertile soils this study examines the crucial link between on farm soil conservation and deforestation in shifting cultivation by modeling forest clearing as an investment in soil for a private farmer more generally by doing so the study attempts to integrate deforestation and soil conservation models which have been separately developed in the literature our policy goal is to arrest tropical deforestation as destruction of global commons caused by land degradation in shifting cultivation while improving the well being of poor shifting cultivators our integrated approach enables joint policy analyses of deforestation and land degradation three welfare enhancing policies are considered the first is agricultural and nonagricultural subsidies affecting farm and nonfarm income opportunities the second is fiscal and tenure policies affecting discount rates our question is whether the link between forest clearing and soil fertility alters the outcomes of these two standard macroeconomic policies commonly found in the literature the third policy or program is various soil conservation measures affecting soil regeneration and erosivity on already cleared lands this article examines a very important question which has received little attention in previous theoretical works can soil conservation reduce deforestation this study confirms anti deforestation effects of the promotion of nonfarming activities a common and often emphasized finding in previous works among shifting cultivators more importantly it also demonstrates that improving various soil conservation measures not only discourages forest clearing among shifting cultivators but also tends to have greater effects on forest protection than promoting nonfarming activities contrarily agricultural price subsidy or technological progress gives rise to the opposite outcome and lowering the farmer s discount rate or improving tenure security encourages him her to clear more forests just to accumulate soil

how well do theories of job matching explain variations in job satisfaction across education levels evidence for uk graduates using ordered probit estimation technique this paper examines the job satisfaction of recent uk graduates focussing primarily on explaining job satisfaction in terms of individuals matching to jobs with the match depending on reservation returns information sets and job offer rates only limited support can be found for the argument that job matching explains higher job satisfaction in addition stylizing graduates as a peer group who form satisfaction levels based on their rankings relative to each other we examine whether or not education quality which raises peer group status and increases the job offer rate is systematically related to job satisfaction the results broadly support the hypothesis that job satisfaction is neutral across graduates of different education qualities however our specification tests indicate that ordered probit estimation may not be fully appropriate for identifying the characteristics of those with high job satisfaction

stock market crashes and dynamics of aftershocks abstract we begin with the intuitive observation that short term business as usual process and bubble rising looks like an accelerated energy before an earthquake in such a framework the aftershocks resemble the correction process of the stock market we investigate the statistical properties of stock returns in the financial markets just after a major market crash it is found that the aftershocks obey the well known gutenberg richter simple rule in geophysics our empirical observations show that the statistical properties of aftershocks sequences in the crashes of late 90s and early 00s are essentially different from the ones observed a decade earlier

sustainable land use management under biodiversity lag effects the destruction of natural habitats for agricultural production results in local biodiversity loss biodiversity loss in turn affects agricultural production indirectly through a range of biodiversity dependent ecosystem services land conversion thus results in a negative externality mediated by changes in biodiversity when the consequences of this externality are delayed in time lack of internalization results in overshoot and collapse dynamics which are undesirable from a sustainability perspective here we emphasize the importance of forward looking policies for the long term sustainability of human nature interactions we show that the internalization of this externality through a land tax can result in several win win effects in the long run first more biodiversity is preserved at equilibrium which increases the carrying capacity and total well being of the human population second a taxation path that maximizes the discounted sum of human utilities prevents or greatly alleviates overshoot and collapse crises thus increasing the sustainability of the system in particular this result holds in the case of imperfect information regarding the precise temporal dynamics of biodiversity loss suggesting that the design of efficient land use management policies is possible despite incomplete ecological data this study highlights the need to internalize biodiversity dependent externalities through economic incentives especially under uncertainty regarding long term ecological dynamics

market liquidity hedging and crashes in the absence of significant news hedging strategies were blamed for the stock market crash of october 1987 but traditional models cannot explain how a relatively small amount of selling could cause so large a price drop the authors develop a rational expectations model in which prices play an important role in shaping expectations markets are much less liquid in their model than in traditional models discontinuities or crashes can occur even with relatively little hedging the model is consistent with theories as disparate as keynes beauty contest insights and thom s catastrophe analysis and suggests means to reduce volatility copyright 1990 by american economic association

a note on soil depth failing markets and agricultural pricing comment abstract bulte and van soest bulte e van soest d 1999 a note on soil depth failing markets and agricultural pricing journal of development economics 58 245 254 argue that higher agricultural output prices result in greater soil conservation when labor markets function well but have ambiguous effects when labor markets are absent the latter result is not attributable to labor market failure but rather occurs whenever labor supply is less than perfectly elastic consistent with the more general model presented here empirical evidence from a number of developing countries suggests that well functioning labor markets are associated with decreases in investment in soils

trade tragedy and the commons we develop a theory of resource management where the degree to which coun tries escape the tragedy of the commons and hence the de facto property rights regime is endogenously determined three forces determine success or failure in resource management the regulator s enforcement power the extent of har vesting capacity and the ability of the resource to generate competitive returns without being extinguished the model can explain heterogeneity across coun tries and resources in the effectiveness of resource management and it predicts that changes in prices population and technology can cause transitions to better or worse management regimes jel p14 q21 q22 q23 q32 many of the world s major renewable resource stocks are in a state of decline this is true for capture fisheries for forests in developing countries and for many measures of the biosphere s health other renewable resources including many species of wildlife marine mammals and coral reefs are also under threat while poverty and government corruption are surely respon sible for some of this record particular emphasis is often placed on the potentially damaging role played by international trade this emphasis is not surprising given that natural resource products are a key export for much of the developing world and property rights over renewable resources are both difficult to define and poorly enforced but property rights are not an immutable country characteristic such as weather mineral deposits or topography they are instead market institutions developed to facilitate transactions and protect scarce resources consequently changes in prices technology and other effects of market integration may alter the de facto property rights regime and lead to impacts quite dif ferent from those predicted by existing analyses the purpose of this paper is to examine renew able resource use within a framework where the enforcement of property rights and hence the efficacy of resource management is endogenously determined we develop a theory where an existing government regulates the use of a renewable resource by a set of agents who have a right to harvest the resource could be a fishery forest stock aquifer etc and we assume it is local and therefore contained within one country the govern ment sets rules limiting harvests but agents may cheat on these allocations and risk punishment property rights are endogenous in this framework because the government must account for agents incentive to cheat as a result the effective protection for the resource or what we refer to as the de facto property rights regime may be far from perfect even though property rights would be perfectly enforced if there was no monitoring problem

agri environmental policies in the eu and united states a comparison abstract agri environmental policies aeps in the united states and the european union are examples of payments for environmental services that pay farmers to reduce the negative externalities of agricultural production while serving as a means to transfer public funds to farmers we show that despite similar origins aeps in the two regions differ both in their specific objectives and in their implementation for example aeps in most member states of the eu 15 have the additional objective of using agriculture as a driver for rural development this objective is achieved by compensating farmers for the private delivery of positive public goods such as attractive landscapes produced by agriculture the rationale is market failure and there is empirical evidence that europeans are willing to pay for such positive externalities no comparable provision exists in u s policy by contrast u s aeps focus almost entirely on reducing agriculture s negative externalities such as soil erosion second we find that u s programs are more targeted than their eu counterparts and take opportunity cost into account the eu programs on the other hand address a wider range of externalities and are focused more on the paying for a particular farming process than reducing specific negative externalities the eu takes a broader view of aeps than does the united states both in terms of type of activity that can be funded and by using less targeting by land characteristics and so the european program could be more easily used as a mechanism for transferring income to producers despite this we find evidence that many of the amenities targeted by the programs are demanded by the population

the accumulation of dis advantage the intersection of gender and race in the long term wage effect of marriage a sizable literature examines whether and why marriage affects men s and women s wages this study advances current research in two ways first whereas most prior studies treat the effect of marri