measuring and improving the performance of customs valuation controls an illustration with gabon modern customs administrations aim to both facilitate legal trade and combat fraud to meet this dual objective many customs administrations in developing countries must give risk management a highly prominent role in this context of modernisation this paper first provides stylised facts on the performance of the customs controls carried out at the gabon border then we compare gabon s granular import customs data with international trade statistics based on this comparison we identify undetected fraud and present a methodology to target ex post audits finally we define indicators to monitor the performance of customs valuation controls

commodity price shocks and civil conflict evidence from colombia how do income shocks aect armed con ict theory suggests two op posite eects if labor is used to appropriate resources violently higher wages may lower con ict by reducing labor supplied to appropriation this is the opportunity cost eect alternatively a rise in contestable income may increase violence by raising gains from appropriation this is the rapacity eect our paper exploits exogenous price shocks in inter national commodity markets and a rich dataset on civil war in colombia to assess how dierent income shocks aect con ict we examine changes in the price of agricultural goods which are labor intensive and natural resources which are capital intensive we focus on coee and oil the two largest exports we nd that a sharp fall in coee prices in the 1990s increased violence dierentially in regions growing more coee by lower ing wages and the opportunity cost of joining armed groups in contrast a rise in oil prices increased violence dierentially in the oil region by in creasing municipal revenue siphoned through rapacity this pattern holds in several other agricultural and natural resource sectors providing robust evidence that price shocks aect con ict in opposite directions depending on the factor intensity of the commodity

integration of spatial markets studies of spatial market integration draw their implications from a theory which assumes that there are no intraregional transport costs an alternative theory is offered based on the assumptions that buyers and sellers are spatially dispersed and intraregional transport costs are significant this implies that the market is a linked oligopoly or oligopsony and that market integration tests are tests of alternative oligopoly price formation processes for example collusive basing point pricing produces results typically assumed to imply efficiently integrated markets while competitive fob pricing does not the theoretical implications are illustrated with an analysis of hog prices in canada

market integration an application to international trade in cotton agricultural commodities are differentiated frequently by quality or country of origin this paper proposes two complementary tests bivariate price regressions and hedonic index estimation as methods to identify whether differentiated products are amenable to treatment as a homogenous commodity these price linkage tests represent necessary rather than sufficient conditions for aggregation and must be supplemented by information on market structure analysis of the international cotton market suggests a distinction between extra long and other staple lengths but not by country of origin after controlling for staple length

cointegration tests and spatial price linkages in regional cattle markets this analysis empirically evaluates spatial linkages in regional cattle markets using cointegration tests of regional price series several markets were not cointegrated over the 1980 through 1987 period however significant increases in cointegration of several regional livestock markets are observed through the 1980s the increased cointegration parallels significant structural changes in the livestock industry a formal analysis of market characteristics reveals that distances between markets industry concentration ratios market volumes and market types have significant influences on cointegration relationships between markets

entrepot trade and smuggling in west africa benin togo and nigeria official trade statistics indicate very little intra african trade but this is often because of the prevalence of unrecorded trade particularly smuggling this paper explores smuggling from benin and togo into nigeria nigeria has very high import tariffs and bans on certain products togo and benin have deliberately maintained low import barriers to facilitate an entrepot role vis a vis nigeria and land locked sahelian countries togo competes at a geographic disadvantage relative to benin for access to the nigerian market and compensates with lower transit taxes the volume and composition of cross border trade is analysed using data obtained from benin and togo customs authorities as well as interviews with traders and customs officials in both countries benin and to a lesser extent togo are the origin of a very large volume of transshipment of precisely those products which are heavily protected in nigeria such as used cars cloth and rice it is common knowledge in benin and togo that these imports although declared for domestic consumption or transit to other countries are in fact overwhelmingly intended for nigeria smuggling is a major source of income and employment in benin and togo but provides a fragile and unreliable foundation for economic development

quota hopping in bond diversion we show that the u s in bond system of imports may be used by firms to illegally avoid trade barriers a practice known as in bond diversion the illicit scheme involves declaring chinese exports bound for mexico but diverting them to the u s market while in transit thus creating a gap between chinese and mexican reports using the phaseout and removal of u s quotas at the end of the multifiber agreement as a policy experiment as well as variation in quota bindingness across products we show that quota bound products were associated with larger trade gaps which shrunk following the quota removals jel f13 o17 o19

from maize to haze agricultural shocks and the growth of the mexican drug sector understanding how economic incentives affect illegal drug production is essential for crafting policies in response to the international drug trade policymakers typically face a choice between two strategies targetingcriminalgroupsvialawenforcement andofferingproducersincentivestoengage in alternate activities yet little is known about how the returns to alternate legal activities affect drug supply we contribute to this literature by examining how shocks to legal commodity prices affect the drug trade in mexico our analysis exploits exogenous movements in the mexican maize price stemming from weather conditions in u s maize growing regions as well as exports of other major maize producers using data on over 2200 municipios spanning 1990 2010 we show that lower prices differentially increased the cultivation of both marijuana and opium poppies in municipios

land tenure price shocks and insurgency evidence from peru and colombia abstract the paper examines how property arrangements a key determinant of rural income influence armed conflict in the presence of commodity price shocks using detailed data on district level land tenure crop produce and conflict intensity in peru and colombia estimates show that exogenous negative price shocks increase the intensity of conflict in districts with a greater presence of individual ownership relative to other types of land tenure the finding is consistent with small landowners in the export sector experiencing a sharper downturn in labor market outcomes thus reducing the opportunity cost of participating in insurgent groups

output input and productivity measurement in u s agriculture 1948 79 tornqvist theil indexes of outputs and inputs are constructed these data are used to construct indexes of productivity growth over the postwar period the productivity indexes can be derived from a flexible multioutput multifactor representation of the structure of production constrained to constant returns to scale total factor productivity grew at an average annual rate of 1 75 compared with 1 70 per year estimated by the u s department of agriculture the similar estimates of productivity growth overshadow some important differences in measurement of individual inputs the major effort in measuring agricultural productivity is undertaken by the u s department of agriculture usda an american agricultural economics association task force on measuring productivity has examined the sources and procedures used in constructing the official statistics see loomis and barton lambert barton and durost the task force recommended that the usda adopt a series of specific improvements for constructing certain inputs and use an indexing procedure that does not impose a priori restrictions on the structure of production 1 this paper presents revised indexes of outputs and inputs the data are used to construct indexes of productivity growth over the postwar period the productivity indexes can be derived from a flexible multioutput multifactor representation of the structure of production the translog transformation function constrained to constant returns to scale 2 the indexes of outputs and inputs have the same form and their ratio coincides with the estimate of productivity growth

economic determinants of land invasions this study estimates the effect of economic conditions on redistributive conflict we examine land invasions in brazil using a panel data set with over 50 000 municipality year observations adverse eco nomic shocks instrumented by rainfall cause the rural poor to invade and occupy large landholdings this effect exhibits substantial heterogeneity by land inequality and land tenure systems but not by other observable variables in highly unequal municipalities negative income shocks cause twice as many land invasions as in municipalities with average land inequality cross sectional estimates using fine within region variation also suggest the importance of land inequality in explaining redistributive conflict i introduction c onflict over land is endemic to many rural econo mies in environments marked by a highly skewed distribution of property incomplete land and credit markets poorly or unevenly enforced property rights and weak political institutions agents often resort to extralegal means to improve their economic positions the poor frequently invade private properties and occupy them until either forcibly expelled or granted official titles land conflict which is prevalent in many countries such as brazil south africa uganda and venezuela may distort the allocation of resources in the agricultural sector away from productive uses and thereby contribute to the persistence of rural poverty how do economic conditions affect this redistrib utive conflict this paper explores this question using a rich municipal level data set of 5 299 land invasions from 1988 to 2004 in brazil we follow miguel satyanath and sergenti 2004 by using rainfall as a source of exogenous variation to study the relationship between income and conflict and we find that adverse economic shocks cause the rural poor to invade large landholdings this effect exhibits considerable het erogeneity by land inequality and land tenure systems in highly unequal municipalities negative income shocks cause twice as many land invasions as in municipalities with average land inequality the effect of income shocks is even stronger in highly polarized municipalities as measured by the degree of bimodality in the land distribution cross sectional estimates using fine within region variation also suggest the importance of land inequality in explaining redistributive conflict we also find that income shocks cause significantly more land invasions in municipalities with a greater proportion of land under fixed rent contracts by contrast we find no evidence of heterogeneity on a range of other political and socioeconomic variables including political competition sharecropping police expenditures and social welfare spending recent microeconometric studies have examined two

does industrialization build or destroy social networks abstract this article estimates the relationship between changes in industrialization and changes in social networks measures in indonesia during 1985 97 using repeated cross sections of nationally representative surveys we analyze a rich set of social interaction measures including various measures of voluntary associational activity levels of trust and informal cooperation districts that experienced rapid industrialization showed significant increases in most measures of social interaction however districts that neighbor rapidly industrializing areas exhibited high rates of out migration significantly fewer community credit cooperatives and a reduction in mutual cooperation as assessed by village elders manufacturing growth can be thought of as a proxy for income growth here the findings are contrary to several recent claims regarding the role of social capital in economic development

theories of share tenancy a critical survey for the past 2 decades the problems of agricultural tenancy have attracted a great deal of attention not only from agricultural economists but also from economists in general as a typical example of agencyprincipal contract relations despite the prolific growth of literature both theoretical and empirical there has been little convergence in opinions on tenancy contracts the divergence has been especially great on the understanding of the causes and the effects of sharecropping tenancy much confusion underlying the widely divergent perspectives has stemmed from partial treatments of contractual choice which unduly limit the optimizing behavior of contracting parties and the options of contract forms this essay aims at clarifying the sources of the confusion by reviewing the past literature in light of the more general theory of agency principal relations the agency theory in order to examine the problems of various theoretical models in a unified framework in section ii we first develop the basic framework of a general model of tenancy contract in section iii we clarify in terms of the general model contradictions latent in the traditional marshallian theory which asserts that share tenancy is inefficient because of the disincentive effect of cropsharing on the tenant s work effort in section iv we attempt to show that recent efforts to reconstruct the theory based on the traditional assumption have not yet been quite successful section v draws implications and testable hypotheses from more general theories incorporating the aspects of risk and uncertainty section vi tests allocational and distributional implications of those alternative hypotheses based on the summary of evidence col

income distribution political instability and investment abstract this paper successfully tests on a sample of 71 countries for the period 1960 85 the following hypotheses income inequality by fuelling social discontent increases sociopolitical instability the latter by creating uncertainty in the politico economic environment reduces investment as a consequence income inequality and investment are inversely related since investment is a primary engine of growth this paper identifies a channel for an inverse relationship between income inequality and growth we measure socio political instability with indices which capture the occurrence of more or less violent phenomena of political unrest and we test our hypotheses by estimating a two equation model in which the endogenous variables are investment and an index of socio political instability our results are robust to sensitivity analysis on the specification of the model and the measure of political instability and are unchanged when the model is estimated using robust regression techniques

a theory of political transitions we develop a theory of political transitions inspired by the experiences of western europe and latin america nondemocratic societies are controlled by a rich elite the initially disenfranchised poor can contest power by threatening revolution especially when the opportunity cost is low for example during recessions the threat of revolution may force the elite to democratize democracy may not consolidate because it is redistributive and so gives the elite an incentive to mount a coup highly unequal societies are less likely to consolidate democracy and may end up oscillating between regimes and suffer substantial fiscal volatility

exogenous degradation in the commons field experimental evidence abstract this article presents the results from framed field economic experiments in rural colombia that aim to explore the behavioral responses of resource users to exogenous changes in the availability of a common pool resource in the first 10 rounds of the experiment all subjects played at a baseline with the same initial resource availability in the subsequent rounds the experimenters exogenously changed the resource size including mild and strong reductions in the resource size and rebounds to original size results show that subjects react to strong reductions in resource availability by increasing appropriation from the resource this behavior holds for intense and persistent as well as for progressive reductions in resource availability in addition subjects that experience a reduction in the resource availability followed by a rebound to the initial resource size appropriate more than those subjects who did not experience any change in the resource availability

the countercyclical aspects of the u s meat import act of 1979 the u s meat import act of 1979 the so called countercyclical meat import bill was signed into law on the last day of that year by president carter this law which reflects a desire to help stabilize the fluctuations that have taken place in cattle inventory numbers and prices has received wide attention by the u s livestock industry and countries exporting to the united states reeves 1979 u s congress there is evidence that the united states is a price maker at the international level as a result of being the world s largest beef importer producer and consumer simpson consequently a major change in the u s meat import law can be expected to have a tangible influence on international trade in beef and the policies set by both beef exporting and importing countries as well as on the u s cattle industry the purpose of this note is to analyze some potential effects of the new u s meat import law under two radically different assumptions about change in cattle inventory to determine if the act really is countercyclical i e resulting in a higher import quota when u s beef production is declining and vice versa in a lower quota level industry these results contain implications for furher refinements in such stabilizing schemes

national trade policies and smuggling in africa the case of the gambia and senegal summary much of inter regional trade in africa is unrecorded and consists of smuggling the gambia is almost wholly enclosed within senegal yet official trade statistics show almost no trade between the two countries failing to capture large scale smuggling smuggling reflects pre colonial traditional trading relationships the artificial nature of borders created in the colonial era and the disparities in trade policies between the two countries following independence inducing large cross border price differentials for goods this paper documents the magnitude of trade protection in the two countries the resulting price differences and estimates the volume of smuggling

supply and demand functions for multiproduct u s cash grain farms biases caused by research and other policies this study presents new estimates of supply and demand elasticities for u s multiproduct cash grain farms and estimates of input and output bias effects caused by public and private crop research extension and farmers schooling the study also shows that the social rate of return to public crop research is large about 62 percent

tariffs enforcement and customs evasion evidence from india we examine the effect of tariff policies on evasion of customs duties in the context of the trade reform in india of the 1990s by exploiting the variation in tariff rates across time and products we identify a robust positive elasticity of evasion with respect to tariffs a second contribution of the paper is to provide some evidence on the impact of enforcement while we cannot identify the direct impact of enforcement on evasion we can establish the extent to which enforcement related factors such as product characteristics that determine the ease of detection of evasion affect the evasion elasticity the results render support to the hypothesis that improvements in enforcement can reduce the responsiveness of evasion to tariffs

the political consequences of income shocks explaining the consolidation of democracy in france abstract this study analyzes the circumstances that enabled france to become in the late nineteenth century the first stable parliamentary democracy with universal male suffrage in europe it establishes a causal relationship between short term variations in local income and the electoral support for the coalition of republican parties that represented the newly established regime the results suggest the republican coalition won the parliamentary elections because most french regions did not suffer from transitory negative income shocks stemming from heavy precipitations they thus raise questions about the rationality of voters and ultimately the actual causes of the consolidation of democracy in france

dynamic fertilizer nutrient demands for corn a cointegrated and error correcting system past studies of the demand for fertilizer have typically been based on static models which assume that adjustments toward equilibrium are instantaneous this article builds on past studies by developing a dynamic model of nutrient demands of corn unit root and cointegration tests demonstrate that fertilizer demands of corn are dynamic therefore statistically correct estimates can be obtained using a dynamic model a set of error correction models for nitrogen phosphate and potash use in corn production are estimated results provide strong statistical evidence that nutrient demands of corn are price inelastic both in the short and the long run

property rights and the political organization of agriculture we propose a general equilibrium model where the economic organization of agriculture and the political equilibrium determining the security of property rights are jointly determined in particular because the form of organization may affect the probability and distribution of benefits from future property challenges it may be shaped in anticipation of this impact property rights security may then be secured at the expense of economic efficiency the model provides a framework for understanding why in some contexts land is redistributed primarily via land sales and tenancy markets but via politics and conflict in others we test some implications of the theory using a five decade panel dataset that traces changes in the extent of tenancy and tenancy reform across 15 indian states

estimating the effects of climate shocks on collective violence ardl evidence from india this paper examines the causal relationship between climate shocks and collective violence in india using annual data over the period 1954 2006 we use the ardl bounds testing approach to deal with

a variance components approach to food grain market integration in northern nigeria a variance components methodology is developed for joint tests on a sample of time series of prices for seasonal differences in the price integration of markets the approach requires a statistically adequate number of observations for each market within seasons characterized by constancy of transactions costs among markets the model is applied to eighteen months of weekly grain prices for twenty two villages in northern nigeria results suggest that markets are not well integrated in the six months covering the harvest period implications are drawn for research on market performance in the region

supply demand and technology in a multiproduct industry texas field crops the purpose of this paper is to examine the structure of agricultural production for six texas field crops cotton grain sorghum wheat corn rice and hay which account for nearly 95 of recent field crop value specific objectives are to a test the structure of technology to determine i if output and input utilization choices for individual products are independent of production decisions about other outputs and ii if products and or inputs can be consistently aggregated b estimate a coherent set of interrelated supply functions for the six commodities and input demand functions for fertilizer and hired labor because the empirical focus of this paper is specific to one state the results will be of limited value for interpreting specific production relationships elsewhere however the problem is of common interest in production agriculture and the techniques used demonstrate an important application of dual modeling

polarization politics and property rights links between inequality and growth most efforts to trace the effects of income inequality on growth have focused on redistribution however empirical investigation has not substantiated either the positive association of income inequality with redistribution or the negative association of redistribution with economic growth the authors analyze the effects of inequality in the broader context of social polarization they argue that social polarization whether rooted in income inequality or in ethnic tension makes large changes in current policies including those guaranteeing the security of contract and property rights more likely under a wide range of institutional arrangements the resulting uncertainties in the policy and contractual environment hinder growth they find strong empirical support for both parts of this argument the policy implications of their argument are quite distinct from those of arguments that inequality reduces growth by increasing pressures for redistribution if redistributive policies per se were to blame for the low growth resulting from inequality governments that seek to mitigate income inequality must inevitably confront a tradeoff between equity and growth if on the other hand the insecurity of property rights slows growth in unequal or otherwise polarized societies governments that commit over the long run to particular redistributive policies incur less risk of slowing economic growth fiscal redistribution that reduces inequality may actually increase growth by reducing the risks of political uncertainty

weather shocks agriculture and crime evidence from india we use detailed crime agriculture and weather data from india during the years 1971 2000 to conduct a systematic analysis of the relationship between weather shocks and multiple categories of crime we find that drought and heat exert a strong impact on virtually all types of crimes that the impact on property crimes is larger than for violent crimes and that this relationship has been relatively stable over three decades of economic development we then use seasonal and geographical disaggregations of weather and agricultural cultivation to examine the prevailing hypothesis that agricultural income shocks drive the weather crime relationship in developing countries the patterns we find are consistent with this hypothesis in the case of rainfall shocks but suggest additional mechanisms may play an important role in driving the heat crime relationship consistent with evidence from industrialized countries

a new data set measuring income inequality this article presents a new data set on inequality in the distribution of income the authors explain the criteria they applied in selecting data on gini coefficients and on individual quintile groups income shares comparison of the new data set with existing compilations reveals that the data assembled here represent an improvement in quality and a significant expansion in coverage although differences in the definition of the underlying data might still affect inter temporal and international comparability based on this new data set the authors do not find a systematic link between growth and changes in aggregate inequality they do find a strong positive relationship between growth and reduction of poverty

income shocks and hiv in africa we examine how variation in local economic conditions has shaped the aids epidemic in africa using data from over 200 000 individuals across 19 countries we match biomarker data on individuals serostatus to information on local rainfall shocks a large source of income variation for rural households we estimate infection rates in hiv endemic rural areas increase by 11 for every recent drought an effect that is statistically and economically significant income shocks explain up to 20 of variation in hiv prevalence across african countries suggesting existing approaches to hiv prevention could be bolstered by helping households manage income risk better the relationship between income and health has long been of interest to economists and a lengthy literature documents strong linkages between economic conditions and many important health outcomes currie 2009 there has been much less progress however in understanding the economic foundations of the hiv aids epidemic one of the most important global health challenges such an understanding might yield particular dividends in sub saharan africa ssa where over a million people continue to become newly infected with the disease each year unaids 2010 in this article we explore the role of negative income shocks in shaping the

conflict and distribution abstract we develop a behavioral model that links the level and pattern of social conflict to the societywide distribution of individual characteristics the model can be applied to groups that differ in characteristics such as wealth ethnicity religion and political ideology we settle questions of existence and uniqueness of conflict equilibrium conflict is seen to be closely connected with the bimodality of the underlying distribution of characteristics however in general the conflict distribution relationship is nonlinear and surprisingly complex our results on conflict patterns also throw light on the phenomena of extremism and moderation journal of economic literature classification numbers d63 d72 d74

tax rates and tax evasion evidence from missing imports in china tax evasion by its very nature is difficult to observe we quantify the effects of tax rates on tax evasion by examining the relationship in china between the tariff schedule and the evasion gap which we define as the difference between hong kong s reported exports to china at the product level and china s reported imports from hong kong our results imply that a one percentage point increase in the tax rate is associated with a 3 percent increase in evasion furthermore the evasion gap is negatively correlated with tax rates on closely related products suggesting that evasion takes place partly through misclassification of imports from higher taxed categories to lower taxed ones in addition to underreporting the value of imports

what do we learn from the weather the new climate economy literature a rapidly growing body of research applies panel methods to examine how temperature precipitation and windstorms influence economic outcomes these studies focus on changes in weather realizations over time within a given spatial area and demonstrate impacts on agricultural output industrial output labor productivity energy demand health conflict and economic growth among other outcomes by harnessing exogenous variation over time within a given spatial unit these studies help credibly identify i the breadth of channels linking weather and the economy ii heterogeneous treatment effects across different types of locations and iii nonlinear effects of weather variables this paper reviews the new literature with two purposes first we summarize recent work providing a guide to its methodologies datasets and findings second we consider applications of the new literature including insights for the damage function within models that seek to assess the potential economic effects of future climate change jel c51 d72 o13 q51 q54

the political economy of government responsiveness theory and evidence from india the determinants of government responsiveness to its citizens is a key issue in political economy here we develop a model based on the solution of political agency problems having a more informed an politically active electorate strengthens incentives for governments to be responsive this suggests that there is a role both for democratic institutions and the mass media in ensuring that the preferences of citizens are reflected in policy the ideas behind the model are tested on panel data from india we show that public food distribution and calamity relief expenditure are greater controlling for shocks where governments face greater electoral accountability and where newspaper circulation is highest

climate instability urbanisation and international migration abstractthis paper focuses on climate induced migration we construct a simple theoretical model where in a first step climate shocks accelerate the transition from the traditional to the modern sector leading rural workers to move to urban centres within national borders while in a second step downward pressures on wages due to the greater labour supply in cities push people to engage in international migration to test this hypothesis we exploit a rich panel dataset displaying a representative picture of bilateral migration flows and climatic data across 222 countries for the period 1960 2000 findings suggest that in the next few years the climate induced growth rate of migrant stocks might be in a range between 8 6 per cent and 12 8 per cent especially from developing countries where the level of rural employment is more likely to be affected by climatic shocks

does sharecropping affect long term investment evidence from west bengal s tenancy reforms in india land reform has been high on the political agenda since independence in 1947 and early efforts at abolishing intermediaries are widely credited with having brought about significant social benefits the most prominent type is tenancy reform as it does not extinguish landlords ownership rights tenants who may have benefited from rent ceilings and cannot be evicted still have to pay annual share rent this weakness of rights may fail to create the incentives for effort supply and long term investment that have underpinned the success of land reforms elsewhere effectively adding a dynamic inefficiency to the disincentives created by the marshallian inefficiency of sharecropping this could imply that despite the high political price of implementing land reform in india the schemes so far have failed to reach their productivity and poverty reduction potential

can africa compete with china in manufacturing the role of relative unit labor costs in this paper examine sub saharan africa s ssa bilateral trade and cost competitiveness with china we review patterns of bilateral trade between ssa and china showing an extraordinary imbalance in the structure of trade in that china overwhelmingly exports manufactured products to ssa and almost exclusively imports primary products in return our principal means of assessing the competitiveness of ssa s manufacturing sector vis a vis china are measures of relative unit labor costs rulc we find that african rulc levels have generally been very high relative to china but declined over the 2000s as china s wages have risen faster than chinese productivity while the reverse is true for the ssa countries in our sample nevertheless rulc vis a vis china remained elevated for many ssa countries as of 2010 generally high rulc along with weaknesses in the business climate suggest that most ssa countries are unlikely to be competitive in labor intensive manufacturing any time soon

estimating long run economic equilibria with stochastic trends an asymptotic theory is provided to analyze a menu of currently existing estimators of cointegrated systems we study in detail the single equation ecm seecm approach of hendry our theoretical results lead to prescriptions for empirical work such as specifying seecm s nonlinearly and including lagged equilibrium relationships rather than lagged differences of the dependent variable as covariates simulations support these prescriptions and point to problems of overfitting not encountered in the semiparametric approach of phillips and hansen 1990

the effects of weather induced migration on sons of the soil riots in india migration is thought to cause sons of the soil conflict particularly if natives tend to be unemployed using data from india the authors investigate the causal effect of domestic migration on riots by instrumenting for migration using weather shocks in migrants places of origin they find a direct effect of migration on riots but do not find that this effect is larger in places with more native unemployment they argue and find evidence that migration is less likely to cause rioting where the host population is politically aligned with the central government politically privileged host populations can appease nativists and reduce migration through means that are less costly than rioting without these political resources hosts resort to violence beyond furthering the sons of the soil literature the authors detail a political mechanism linking natural disasters and possibly climate change and environmental degradation to riots and demonstrate a widely applicable strategy for recovering the causal effect of migration on violence

voluntary export restraints as protection policy the u s beef case there are several well known implications of international trade theory which are relevant to our study with a tariff an importing country s welfare can improve only if the excess supply curve is upward sloping under the large country assumption bhagwati has shown that a quota used by an importer can be equivalent to a tariff and mintz has contrasted features of tariffs quotas and vers empirical work has focused largely on the effects of tariffs and equivalent quotas generally exporting countries lose from such trade barriers in contrast we find that exporting countries gain and importing countries lose with a ver we also contrast the gains and losses of vers in the case of frozen boneless beef to an optimal tariff and optimal export tax the theoretical implications of vers for beef exporters were first recognized by freebairn and gruen

collective action and the group size paradox according to the olson paradox larger groups may be less successful than smaller groups in furthering their interests we address the issue in a model with three distinctive features explicit intergroup interaction collective prizes with a varying mix of public and private characteristics and nonlinear lobbying costs the interplay of these features leads to new results when the cost of lobbying has the elasticity of a quadratic function or higher larger groups are more effective no matter how private the prize with smaller elasticities a threshold degree of publicness is enough to overturn the olson argument and this threshold tends to zero as the elasticity approaches the value for a quadratic function we also demonstrate that these results are true irrespective of whether we examine group sizes over the cross section in some given equilibrium or changes in the size of a given group over different equilibria

multiple input multiple output production choices and technology in the u s wheat region duality theory motivates a translog expected profit function consistent with multiple products price uncertainty preseason climate constraints acreage control policies and possibly nonhomothetic technology although multiple outputs are allowed enterprise specific data is not necessary instead time series measures of output revenues and expected prices input expenses and prices and fixed input flows are employed appropriate measures of elasticities of choice returns to size and biases in technological change are derived results indicated decreasing returns to size rather limited though complementary responsiveness of choices to price changes and the nature of biases in technological changes

what causes violent crime this study uses panel data of intentional homicide and robbery rates for a sample of developed and developing countries for the period 1970 1994 based on information from the united nations world crime surveys to analyze the determinants of national crime rates both across countries and over time a simple model of the incentives to commit crimes is proposed which explicitly considers possible causes of the persistence of crime over time criminal inertia a panel data based gmm methodology is used to estimate a dynamic model of national crime rates this estimator controls for unobserved country speci ce ects the joint endogeneity of some of the explanatory variables and the existence of some types of measurement errors a icting the crime data the results showthat increases in income inequality raise crime rates crime tends to be countercyclical and criminal inertia is signi cant 2002 elsevier science b v all rights reserved

using weather variability to estimate the response of savings to transitory income in thailand this paper measures the extent to which farmers are able to use savings and dissavings to smooth consumption in response to unexpected shocks to income time series information on regional rainfall is used to construct estimates of transitory income due to rainfall shocks the relationship between these measures of transitory income and savings indicates that farm households save a significantly higher fraction of transitory income than nontransitory income jel d91 016 the incomes of farm households in developing countries are notorious for being both low and uncertain policies that increase the incomes of farmers may well be different

influence of trade policies on price integration in the world beef market abstract the article develops three hypotheses about how policy interventions in major trading nations influence price integration in the world beef market simple correlation coefficients tests for significant differences between coefficients and granger causality tests are used to test the hypotheses first segmentation between prices in foot and mouth disease fmd free and fmd endemic countries is found but it is much less than previously assumed second european community policies that closed the e c import market have isolated prices in the e c from other markets these policies also led to greater integration among prices in fmd free and fmd endemic market segments by forcing exporters from both segments to compete directly in new import markets third the u s a is found to be the price leader in world beef markets due not only to market size but also to u s policies that allow transmission of price information from the u s market to the world market but not vice versa

how integrated are world beef markets the case of australian and u s beef markets abstract the objective of the paper is to examine market integration between australian and u s beef prices at the farmgate level if these two prices are found to be integrated then it can be alleged that australian beef prices can be used as a world price in empirical analyses and or as a reference price to measure the level of support accorded the u s beef sector co integration analysis and a time varying parameter estimation procedure based on the kalman filter model are applied the paper distinguishes between steer and cow beef segments and it uses monthly data over the 1972 1 to 1993 2 period the results indicate that australian and u s beef prices are co integrated albeit not fully and that the degree of convergence between the various price pairs has not substantially increased over time the results also suggest that australian prices can not unequivocally be adopted as a world price in empirical analyses

non stationarity and the import demand for virgin olive oil in the european union the aim of this study is to analyse the importation of virgin olive oil to european union countries paying special attention to the spanish export contribution the method used is based on the estimation of an imports demand system the novelty of the paper lies not in the modelling approach but in the explicit consideration of the univariate characteristics of series that is included in the analysis since prices are non stationary cointegration among them has been tested results indicate that they are cointegrated and that homogeneity holds as a result relative prices are included in the imports demand system structural change is also considered so as to account for the entrance of both spain and greece into the eu during the period studied results demonstrate the leadership of spain within the eu virgin olive oil market as well as the increasing competitiveness of greek oil

fertilizer demand in greece abstract limiting fertilizer use is becoming an important policy objective world wide however the debate on appropriate policy measures is far from settled and evidence on fertilizer demand elasticities is still insufficient past studies on fertilizer demand leave several methodological and empirical issues open this paper aims to contribute to the debate on the methodology of estimating fertilizer demand using single equation methods dynamic aspects are also considered using error correction modelling methodology and cointegration techniques the model is applied using data from greece short run and long run price elasticities of fertilizer demand with respect to own price and to output prices show significant response to price changes and the adjustment coefficient of fertilizer use to the error correction term was found to be fairly rapid the main policy conclusion of the paper is that reducing agricultural support may be an alternative and perhaps more effective way of reducing fertilizer demand than increasing fertilizer prices

the economics of water scarcity and variability does the availability or variability of water matter for the economy does it meaningfully impact the growth and development trajectory of a country it may seem surprising that answers to these most basic of questions remain elusive the aim of this paper is to summarize recent work on the economic impacts of water scarcity and variability the paper finds that there is strong evidence that variations in rainfall and water availability have significant impacts on particular sectors such as agriculture human capital and even conflict but paradoxically evidence of impacts on economic growth and other measures of aggregate economic activity remains ambiguous the paper explains reasons for this anomaly and explores the pathways through which water impacts the economy the paper provides a synthesis of key developments in the literature identifies methodological gaps and suggests policy solutions

selling labor low wage responses to productivity shocks in developing countries productivity risk is pervasive in underdeveloped countries this paper highlights a way in which underdevelopment exacerbates productivity risk productivity shocks cause larger changes in the wage when workers are poorer less able to migrate and more credit constrained because of such workers inelastic labor supply this equilibrium wage effect hurts workers in contrast it acts as insurance for landowners agricultural wage data for 257 districts in india for 1956 87 are used to test the predictions with rainfall as an instrument for agricultural productivity in districts with fewer banks or higher migration costs the wage is much more responsive to fluctuations in productivity

market integration efficiency of arbitrage and imperfect competition methodology and application to u s celery this paper develops and applies a methodology to test for efficiency of interregional commodity arbitrage application of the methodology requires only time series data on prices for alternative cities regions countries or product forms yet the approach is capable of generating evidence on a number of market parameters including market integration arbitrage efficiency the magnitude of marketing margins product substitutability and competitiveness of markets estimation is based on a switching regression model with three regimes efficient arbitrage relative shortage and relative glut results from application of the model to u s celery marketing indicated significant departures from efficient arbitrage for both california and florida celery

distributive politics and economic growth a crude distinction between economics and politics would be that economics is concerned with expanding the pie while politics is about distributing it in this paper we analyze the relationship between the two we focus on how an economy s initial configuration of resources shapes the political struggle for income and wealth distribution and how that in turn affects long run growth our main conclusion is that inequality is conducive to the adoption of growth retarding policies we derive this result from a simple political economy model of growth and present cross country evidence consistent with it the key feature of our model is that individuals differ in their relative factor endowments we distinguish between two types of factors an accumulated factor called capital and a nonaccumulated factor called labor growth is driven by the expansion of the capital stock which is in turn determined by individual saving decisions long run growth is endogenous as the aggregate production function is taken to be linearly homogeneous in capital and productive government services taken together the provision of government services is financed by a tax on capital because government services are productive a small tax on

take what you can property rights contestability and conflict weak property rights are strongly associated with underdevelopment low state capacity and civil conflict in economic models of conflict outbreaks of violence require a prize that is both valuable and contestable this paper exploits spatial and temporal variation in the availability of land with title that is contestable by private actors to explore the relationship between in secure property rights and civil conflict in the brazilian amazon the results suggest that resolving this contestability of title at the local level could eliminate substantively all local land related violence but might increase conflict in areas where title remained contestable

swords or plowshares a theory of the security of claims to property this paper develops a general equilibrium model of the allocation of resources among appropriative and productive activities the model emphasizes the distinction between offensive weapons which are the instruments of predation and fortifications which provide defense against predation the analysis of this model shows how the equilibrium security of claims to property is determined the analysis focuses on the possibility of a nonaggressive equilibrium in which no resources are allocated to offensive weapons and claims to property are fully secure we also analyze the complex relation between economic welfare and the security of claims to property we find for example that a relatively poor agent could be better off in an equilibrium with less secure claims to property

does the law of one price really hold for commodity prices in spite of the empirical failure of the law of one price it is usually assumed that commodity prices are perfectly arbitraged at least in the long run this paper argues that this assumption is counterfactual and that much of the empirical evidence provided to support it is flawed and affected by econometric shortcomings spurious regressions nonstationarity in the data inappropriate use of first differences an alternative methodology co integration by which a long run relationship between nonstationary series can be tested is proposed tests of nonstationarity and co integration for a group of commodities show quite uniformly that the law of one price as a long run relationship fails and that deviations from the pattern are permanent

land inequality and conflict intensity this paper investigates the impact of land inequality on conflict intensity a fundamental distinction with the existing literature lies in the nature of inequality under consideration we investigate how land inequality across landlords only influences the intensity of the fight against a rebel group comprised of landless individuals we show that conflict intensity is non monotonic in land inequality in particular the most severe conflicts occur for intermediate land inequality levels moreover a pareto improving and thus voluntary transfer of land from the smaller to the larger landlord may exist

economic shocks and crime evidence from the crash of ponzi schemes abstract in november 2008 colombian authorities dismantled a network of ponzi schemes making hundreds of thousands of investors lose tens of millions of dollars throughout the country using original data on the geographical incidence of the ponzi schemes this paper estimates the impact of their breakdown on crime we find that the crash of ponzi schemes differentially exacerbated crime in affected districts confirming the intuition of the standard economic model of crime this effect is only present in places with relatively weak judicial and law enforcement institutions and with little access to consumption smoothing mechanisms such as microcredit in addition we show that with the exception of economically motivated felonies such as robbery violent crime is not affected by the negative shock

estimation of dynamic maize supply response in zambia abstract increased attention on government pricing policies among african nations leads directly to a need for information about producer responses to price adjustments this is especially true in the case of zambian maize production maize is the most important crop grown in zambia it accounts for more than 80 of the value of marketed food crops is heavily relied on for subsistence consumption and is a staple food in the diet of all zambian citizens this paper analyzes the aggregate price response of maize supply in zambia using a dynamic regression analysis as a result short intermediate and long run multipliers elasticities are measured which can be used to analyze the effect of future price policy changes it was found that a second order rational distributed lag model best fits the available data estimates of short run elasticities of supply for maize and fertilizer prices are 0 54 and 0 48 respectively the corresponding estimated long run elasticities are 1 57 and 1 44

natural resources and conflict a meta analysis of the empirical literature abstract the link between natural resources and conflict has been extensively analysed by the empirical literature yet there is disagreement on both the existence and the type of relationship connecting resources to conflict existing research has focused on demonstrating the impact of resource scarcity or abundance on the risk of conflict but no effort has explored the reasons behind the persisting disagreement among scholars this paper seeks to remedy this imbalance by conducting a meta analysis of the empirical literature that investigates the link between natural resources and conflict we adopt an econometric approach to analyse 900 estimates from 41 articles our results show that both resource scarcity and abundance are associated with a higher probability of conflict the direction and magnitude of the relationship depends on the type of resources and whether climate variables are controlled for specifically the impact of the scarcity of agriculturally related resources such as land and vegetation seems to be mediated by climate variables we also find that the way conflicts and resources are operationalized together with methodological choices and model specifications greatly influence the probability of finding a significant relationship between conflicts and resources

testing market integration a model of spatial price differentials for a tradable good is proposed which avoids the inferential dangers of received methods using static price correlations the proposed method also extracts more information on the causes of price differentials from the same data the method is illustrated using monthly rice price data for postindependence bangladesh including the very substantial regional price shocks during the 1974 famine impediments to market integration are indicated