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

on the salience of ethnic conflict ray acknowledges support from the national science foundation under grants 0421852 and 0617827 esteban is a member of barcelona economics xrea and is grateful for support from the generalitat de catalunya and the cicyt sej 2006 00369 this research is part of the polarization and conflict research project cit2 ct 2004 506084 funded by the european commission dg research sixth framework program

institutions and environmental governance a reconceptualization abstract this article presents the conceptual revisions needed to extend the new institutional approach to environmental governance from its current local and international domains of application to all governance solutions including national environmental and natural resource use policies and multi level governance solutions that are increasingly used to address global environmental change the article suggests that environmental governance is best understood as the establishment reaffirmation or change of institutions to resolve conflicts over environmental resources it also explains why the choice of these institutions is a matter of social justice rather than of efficiency the article suggests a way to understand formal and state centered governance solutions as forms of collective ownership not unlike common property the article demonstrates how institutional analysis can gain resolution by looking at the functional and structural tiers organization of governance functions and formulation of key institutional rules as key aspects of the design of governance institutions

a model of ethnic conflict we present a model of conflict in which discriminatory government policy or social intolerance is responsive to various forms of ethnic activism including violence it is this perceived responsiveness captured by the probability that the government gives in and accepts a proposed change in ethnic policy that induces individuals to mobilize in support for their cause yet mobilization is costly and demonstrators have to be compensated accordingly individuals have to weigh their ethnic radicalism with their material well being to determine the size of their money contribution to the cause our main results are i a one sided increase in radicalism or in population size increases conflict ii a one sided increase in income has ambiguous effects depending on the elasticity of contributions to income iii an increase in within group inequality increases conflict and iv an increase in the correlation between ethnic radicalism and inequality also increases conflict

economic development inequality war and state violence abstract this paper focuses on a political economy of humanitarian emergencies comprising a human made crisis in which large numbers of people die from war and state violence the article analyzes how economic decline income inequality pervasive rent seeking by ruling elites a reduced surplus to threaten the survival income of a large portion of the population a weakening state and competition for control of mineral exports contribute to emergencies economic regress and political decay bring about relative deprivation or perception by influential social groups of injustice arising from a growing discrepancy between what they expect and get

the power to hurt costly conflict with completely informed states according to common explanations of war since war is costly and risky rational states have incentives to strike a bargain and avoid conflict war is then the result of private information about capabilities or resolve and incentives to misrepresent this information or inability to make credible commitments fearon 1995 this article presents another rationalist explanation which does not depend on either of these mechanisms by modeling warfare as a costly bargaining process the paper demonstrates that inefficient fighting can occur in equilibrium under very general assumptions favoring peace specifically it is assumed that peace can be supported in equilibrium and that fighting brings no benefits to either state only costs despite the fact that there exist many agreements that pareto dominate the final settlement states are unable to agree to them and fighting can occur in equilibrium the equilibrium is driven by the ability of states to impose costs on their opponent and bear costs the power to hurt the opponent establishes a range of acceptable settlements and the existence of such a range makes inefficient equilibria possible the article suggests that 1 states may fight if they believe that seeking peace means accepting an unpalatable settlement and 2 a diminished ability to hurt the enemy is a major reason for war termination historical examples are provided to illustrate these results

first movers non movers and social gains from subsidising entry in markets for nature based recreational goods abstract the importance of ecosystem services for mankind stresses the issue of identifying different institutional solutions to effectively secure their adequate provision much focus has been on services of the public good type and instruments like payments for environmental services we extend this work to consider the possible social gains from supporting development of new markets for nature based recreational goods which may alleviate negative externalities caused by congestion problems our three main questions are i why is there a lack of market development ii can there be social gains from intervention and supporting the development of such markets and iii if so then how could such intervention be best performed we use a two stage non cooperative bayesian simultaneous move game model and show that in spite of apparent potential first mover advantages in a developing market demand uncertainty and sunk costs may equally well result in widespread presence of non movers on the supplier side we show that social gains can be made from offering a subsidy towards the sunk costs analysing three possible subsidy schemes we show a that fixed costs may make rationing optimal b that sequential rationing does not necessarily dominate strict rationing because c the more subsidies are offered the larger each subsidy must be to induce participation and that d the longer a single agent on the market may keep market information to himself the better a non rationing scheme will perform relative to rationing schemes finally e subsidies for second mover entry may be optimal in some cases

assessing global economic activity linkages the role played by united states germany and china abstract economic performance increasingly relies on global economic environment due to the growing importance of trade and financial links among countries this work aims to analyze the possible effects of a potential economic growth downturn or one large negative shock in china germany and united states on the growth of other economies we use a univariate global autoregressive approach to assess interdependence across 38 countries we simulate two types of phenomena the first one is a one time large shock of 2 5 standard deviations the second experiment simulates the effect of a hypothetical downturn of the aforementioned economies our results suggest that the united states play the role of a global economy affecting countries all over the globe whereas germany and china play an important regional role

valuing nature lessons learned and future research directions this paper critically reviews the literature on environmental valuation of ecosystem services across the range of global biomes the main objective of this review is to assess the policy relevance of the information encompassed by the wide range of valuation studies that have been undertaken so far published and other studies now cover most ecosystems with aquatic and marine contexts attracting the least attention there is also a predominance of single function valuation studies studies valuing multiple functions and uses and studies which seek to capture the before and after states as environmental changes take place are rare by and large it is the latter types of analyses that are most important as aids to more rational decision taking in ecosystem conservation versus development situations involving different stakeholders local national and global aggregate global scale estimates of ecosystems value are problematic given the fact that only marginal values are consistent with conventional decision aiding tools such as economic cost benefit analysis in general valuation data provide prima facie support for the hypothesis that net ecosystem service value diminishes with biodiversity and ecosystem loss balmford et al 2002 science 297 p 950 future research effort should include complementary research on multiple ecosystem services that seeks to capture the temporal disturbance profile and its causal factors the explicit recognition of multiple interdependent ecosystem services and values poses both conceptual and empirical research challenges it would serve to transform the practice of research in this sub field via the a priori assumption of multiple and inter dependent use instead of independent single use this line of reasoning can then be extended to the institutional arrangements that determine which values are captured new institutional processes and arrangements are probably required in order to best realise benefit streams from multiple ecosystem use and non use provision across a range of different stakeholders

innovative activity and sunk cost abstract we analyze innovative activity in a general framework with time dependent rewards and sunk costs when firms are identical innovation is delayed by an increase in the number of firms or a decrease in the size of the reward when one firm has higher profit potential it is more likely to innovate first our framework generalizes an all pay auction however we show that under certain conditions there is qualitatively different equilibrium behavior

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

linking conflict to inequality and polarization in this paper we study a behavioral model of conflict that provides a basis for choosing certain indices of dispersion as indicators for conflict we show that a suitable monotone transform of the equilibrium level of conflict can be proxied by a linear function of the gini coefficient the herfindahl hirschman fractionalization index and a specific measure of polarization due to esteban and ray jel classification d74 d31

rationalist explanations for war realist and other scholars commonly hold that rationally led states can and sometimes do fight when no peaceful bargains exist that both would prefer to war against this view i show that under very broad conditions there will exist negotiated settlements that genuinely rational states would mutually prefer to a risky and costly fight popular rationalist and realist explanations for war fail either to address or to explain adequately what would prevent leaders from locating a less costly bargain essentially just two mechanisms can resolve this puzzle on strictly rationalist terms the first turns on the fact that states have both private information about capabilities and resolve and the incentive to misrepresent it the second turns on the fact that in specific strategic contexts states may be unable credibly to commit to uphold a mutually preferable bargain historical examples suggest that both mechanisms are empirically plausible

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

socially optimal procurement with tight budgets and rationing abstract we investigate the behaviour of a social planner that secures the supply of a good e g an environmental benefit through contracting with private agents while the social planner seeks to maximise net social benefits she is also controlled with a fixed budget private agents are profit maximising and hold private information concerning their variable costs of production they also have known fixed costs of contracting we find that budget constraints and fixed costs change the optimal contract design in more than one way the social planner minimises costs rations high cost contracts to reduce fixed costs and information rents and distorts contracts for all agent types including low cost agents we find that rationing improves social welfare also even though social costs including tax distortion are explicitly taken into consideration they do not affect the design of optimal contracts when budgets are tight in those cases the budget constraint dominates the solution

property rights and sustainable nature tourism adaptation and mal adaptation in dalarna sweden and maine usa abstract tourism is viewed in many industrial nations as an environmentally friendly way to revitalize distressed rural economies and communities in the forest regions of dalarna and interior maine hopes are pinned on nature based tourism with the presumption that natural capital is underutilized this paper explores the potential and pitfalls of nature tourism as a basis for sustainable rural development in regions where most land is held privately but quasi open access for recreation has been either a right dalarna or a customary entitlement maine the paper applies theories of common pool resources and impure public goods to show that both property regimes are mal adapted for sustainable nature tourism limited exclusion combined with rivalness in land uses mis aligns incentives facing landowners tourists and recreation businesses short term effects include congestion reduced economic opportunity and depressed production of non recreational goods longer term effects include environmental degradation and weak incentives for value added investment tourism development is further impeded by a scale mis match between small ownerships and large efficient recreation management units the analysis suggests that sustainable nature tourism faces four land use challenges

second mover advantages in the strategic adoption of new technology under uncertainty abstract this paper introduces technological uncertainty into a timing game of new technology adoption it is shown that the timing neither necessarily involves first mover advantages in precommitment equilibria reinganum review of economic studies xlviii 1981 395 405 nor rent equalization due to the threat of preemption fudenberg and tirole review of economic studies lii 1985 383 401 rather there may be second mover advantages because of informational spillovers furthermore the model predicts that the equilibrium payoffs will typically be discontinuous and non monotonic in the probability that the new technology is profitable a welfare analysis reveals several market failures and suggests that policy intervention should adequately depend on the nature of uncertainty and the rate of technological progress

governing snowmobilers in multiple use landscapes swedish and maine usa cases snowmobiling growth in north america and sweden creates challenges in governing the commons snowmobiling contributes to the economy of distressed rural regions and enhances residents quality of life but quasi open access to winter landscapes also breeds conflicts among snowmobilers with landowners with other recreationists and with environmentalists and ecosystem health common pool resource and impure public goods theories are used to interpret these conflicts and strategic interactions case studies in sweden and maine yield insights about conditions for sustainable management of multiple use landscapes when property rights are complex and stakeholders diverse the case studies utilize key informant interviews tourist surveys and a contingent valuation exercise to illustrate how innovative governance institutions complemented by infrastructure investments can mitigate conflicts re align incentives and internalize costs local self governance has evolved with state facilitation but without changes in fundamental property law three keys are trail agreements between snowmobile clubs and landowners clubs norm formation and rule enforcement and public private investment in quality trails these arrangements are strained by hot spot congestion free riding and unresolved conflicts with other recreationists d 2004 elsevier b v all rights reserved

the inefficient use of power costly conflict with complete information recent work across a wide range of issues in political economy as well as in american comparative and international politics tries to explain the inefficient use of power revolutions civil wars high levels of public debt international conflict and costly policy insulation in terms of commitment problems this paper shows that a common mechanism is at work in a number of these diverse studies this common mechanism provides a more general formulation of a type of commitment problem that can arise in many different substantive settings the present analysis then formalizes this mechanism as an inefficiency condition that ensures that all of the equilibria of a stochastic game are inefficient this condition has a natural substantive interpretation large rapid changes in the actors relative power measured in terms of their minmax payoffs may cause inefficiency