follower payoffs in symmetric duopoly games this paper compares the leader and follower payoff in a duopoly game as they arise in sequential play with the nash payoff in simultaneous play if the game is symmetric has a unique symmetric nash equilibrium and players payoffs are monotonic in the opponent s choice along their own best reply function then the follower payoff is either higher than the leader payoff or even lower than in the simultaneous game this gap for the possible follower payoff had not been observed in earlier duopoly models of endogenous timing

endogenous timing in duopoly games stackelberg or cournot equilibria abstract simultaneous versus sequential play is studied in an extended game in a preplay stage players decide whether to select actions in the basic game at the first opportunity or to wait until observing their rivals first period actions in one extended game players first decide when to select actions without committing to actions in the basic game the equilibrium has a simultaneous play subgame unless payoffs in a sequential play subgame pareto dominate those payoffs in another extended game deciding to select at the first turn requires committing to an action both sequential play outcomes are the equilibria only in undominated strategies

simple solutions to the initial conditions problem in dynamic nonlinear panel data models with unobserved heterogeneity i study a simple widely applicable approach to handling the initial conditions problem in dynamic nonlinear unobserved effects models rather than attempting to obtain the joint distribution of all outcomes of the endogenous variables i propose finding the distribution conditional on the initial value and the observed history of strictly exogenous explanatory variables the approach is flexible and results in simple estimation strategies for at least three leading dynamic nonlinear models probit tobit and poisson regression i treat the general problem of estimating average partial effects and show that simple estimators exist for important special cases copyright 2005 john wiley sons ltd

being a leader or a follower this paper deals with the analysis of conflicts in duopoly situations in particular with the distribution of roles in the von stackelberg framework which firm will be the leader which firm the follower under what circumstances will firms find a mutually advantageous distribution of roles will they fight for leadership or followship in von stackelberg s analysis of duopoly either firms do not choose their respective roles or they fight for leadership this situation is due to the particular strategy space namely the quantity to produce of an homogeneous good we extend here the strategy space to price quantity pairs we show that if costs are identical or similar then both firms will prefer the role of follower if there is a significant cost differential between the firms then the non cooperative equilibrium can only be of two types either the less efficient firm will act as the leader selling a limited quantity at a low price and the more efficient firm as the follower selling to the residual demand at a higher price or the more efficient firm acting as leader will drive the less efficient firm out of the market by adopting a limit pricing strategy but in so doing that firm makes less profits than if it acts as follower we suggest that it is not unreasonable to expect that firms in a duopoly framework will tend to coordinate on their mutually advantageous role distribution even if they compete in a non cooperative strategic way in terms of both prices and quantities

endogenous stackelberg leadership abstract we consider a linear quantity setting duopoly game and analyze which of the players will commit when both players have the possibility to do so to that end we study a two stage game in which each player can either commit to a quantity in stage 1 or wait till stage 2 we show that committing is more risky for the high cost firm and that consequently risk dominance considerations as in harsanyi and selten 1988 allow the conclusion that only the low cost firm will choose to commit hence the low cost firm will emerge as the endogenous stackelberg leader journal of economic literature classification numbers c72 d43

trade conflict and political integration explaining the heterogeneity of regional trade agreements many historians argue that the main goal of european trade integration was the preservation of peace this paper investigates whether this reasoning is relevant for the eu and other regional trade agreements rtas i provide empirical evidence that customs unions and common markets deep rtas do reduce the probability of war between members partial scope and free trade agreements shallow rtas however have no effect on war probabilities accordingly international insecurity has a differential impact on incentives to create rtas deep rtas are signed between countries that are involved in many interstate disputes and that have low trade costs with the rest of the world whereas the opposite is true for shallow rtas

endogenous stackelberg equilibria with identical firms abstract a symmetric duopoly with two production periods is considered in the first period firms simultaneously choose initial production levels these outputs become common knowledge and then additional second period outputs are chosen simultaneously the market clears after the second period if production costs fall slightly over time a symmetric equilibrium in pure strategies does not exist there are two stackelberg leader follower outcomes in each outcome one firm produces only in the first period and the other produces its best response in the second period this paper allows the firms to use mixed strategies and analyzes a symmetric mixed strategy equilibrium journal of economic literatureclassification numbers d43 l13

endogenous price leadership with an essential input abstract the hamilton slutsky endogenous timing methodology is applied to differentiated duopolies where motivated by access pricing literature one firm owns an essential input sold wholesale to the rival both firms then set retail prices for their differentiated goods the scenario and results are different from standard endogenous timing duopolies encompassing three prices one wholesale two retail rather than two with unique timing game equilibrium which always entails retail price leadership by the input owner thus providing a new and powerful rationalisation for stackelberg the results call into question the generic access pricing assumption that simultaneous moves determine retail downstream prices

social criteria for evaluating population change abstract many applications of economic analysis require social evaluations of alternatives involving different numbers of people in this paper we use the tools of social choice theory to provide an axiomatic formulation of this problem it yields a class of social criteria called critical level generalized utilitarianism this class and its implications are compared with other criteria and are found to yield intuitively appealing results

second mover advantage and price leadership in bertrand duopoly we consider the issue of first versus second mover advantage in differentiated product bertrand duopoly with general demand and asymmetric linear costs we generalize existing results for all possible combinations where prices are either strategic substitutes and or complements dispensing with common extraneous and restrictive assumptions we show that a firm with a sufficiently large cost lead over its rival has a first mover advantage for the linear version of the model we invoke a natural endogenous timing scheme coupled with equilibrium selection according to risk dominance the analysis yields as the unique equilibrium outcome sequential play with the low cost firm as leader

stackelberg versus cournot equilibrium we reconsider stackelberg s classical critique of the cournot duopoly in the framework of endogenous timing for two player games for quantity duopoly we provide different sets of minimal conditions directly on the demand and cost functions yielding respectively the simultaneous and the two sequential modes of play while our findings essentially confirm the predominance of the former they also indicate that the latter is natural under some robust but restrictive conditions no extraneous assumptions such as concavity existence or uniqueness of equilibria are needed and the analysis makes crucial use of the basic results from the theory of supermodular games classification numbers b21 c72 d43 l13 c 1999 academic press

von stackelberg and cournot duopoly choosing roles under what circumstances will firms agree on the choice of roles of leader and follower in the von stackelberg duopoly model a key determinant is the slope of the firms reaction function in either price or quantity space the duopolists will disagree over the choice of roles if they have downward sloping reaction functions each will prefer to be the leader they will also disagree if they have upward sloping reaction functions and similar profit functions each will prefer that the other be the leader preferences between von stackelberg and cournot outcomes are also considered

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

endogenous price leadership we consider a linear price setting duopoly game with differentiated products and determine endogenously which of the players will lead and which one will follow while the follower role is most attractive for each firm we show that waiting is more risky for the low cost firm so that consequently risk dominance considerations as in harsanyi and selten a general theory of equilibrium selection in games mit press cambridge ma 1988 allow the conclusion that only the high cost firm will choose to wait hence the low cost firm will emerge as the endogenous price leader

quantity setting oligopoly with endogenous sequencing abstract this paper investigates endogenous sequencing in a quantity setting oligopoly i formulate an n firm m period model where each firm chooses both how much to produce and when to produce it i find that at least n 1 firms simultaneously produce in the first period in every pure strategy equilibrium this result shows that the generalized stackelberg type outcome never appears in equilibrium except in a duopoly

an aspect of variable population poverty comparisons abstract this paper demonstrates that the property of replication invariance generally considered to be an innocuous requirement for the extension of fixed population poverty comparisons to variable population contexts is incompatible with other plausible variable and fixed population axioms this fact raises questions about what constitutes an appropriate headcount assessment of poverty in terms of whether one should focus on the proportion or the absolute numbers of the population in poverty this observation in turn has important implications for tracking poverty and setting targets for its reduction or elimination

make trade not war this paper analyses theoretically and empirically the relationship between military conflicts and trade we show that the conventional wisdom that trade promotes peace is only partially true even in a model where trade is economically beneficial military conflicts reduce trade and leaders are rational when war can occur because of the presence of asymmetric information the probability of escalation is lower for countries that trade more bilaterally because of the opportunity cost associated with the loss of trade gains however countries more open to global trade have a higher probability of war because multilateral trade openness decreases bilateral dependence to any given country and the cost of a bilateral conflict we test our predictions on a large data set of military conflicts on the 1950 2000 period using different strategies to solve the endogeneity issues including instrumental variables we find robust evidence for the contrasting effects of bilateral and multilateral trade openness for proximate countries we find that trade has had a surprisingly large effect on their probability of military conflict

guns butter and openness on the relationship between security and trade sovereign states arm to defend real or hypothetical interests presumably because they cannot engage in complete long term contracting that would prevent such arming international trade therefore takes place within an essentially anarchic context and we can expect trade regimes and security policies to be related indeed many embargoes sanctions and various other forms of trade restrictions that have been used throughout history and continue to be used today can be considered extensions of security policies whereas some security policies can be attributed to trade policy the relationship between trade and security however has been barely explored within economics we could fairly characterize the prevailing view within the discipline as the classical liberal view according to which the expansion of international trade does not just increase the welfare of the trading partners but can also patch up any differences they might have over other contentious issues solomon polachek 1980 represents a rare articulation of this widely held perspective more boldly it could be argued that the expansion of trade always alleviates conflict by forcing the adoption of measures that manage conflict nevertheless one does not need to dig much into history to show that while trade and economic interdependence can contribute to the peaceful resolution of disputes they are not sufficient by themselves to guarantee the absence of war and the reduction of arming many observers before world war i for example considered that the hitherto unprecedented expansion of trade and interdependence between britain and germany made war unthinkable and impossible yet war occurred and with much ferocity and destruction furthermore as donald kagan 1995 pp 373 80 has argued the british policy of appeasement toward germany during the 1930 s was based on similar arguments about the use of economic caltots to avoid war what can inter

endogenous timing in the presence of non monotonicities the aim of this paper is to generalize the endogenous timing game proposed by hamilton and slutsky games and economic behavior 1990 2 pp 29 46 by allowing the payoff or the marginal payoff of a player to become non monotonic with respect to the strategy of the opponent we propose a taxonomy of the subgame perfect nash equilibria based on the characteristics of the payoff functions proposed by eaton canadian journal of economics 2004 37 pp 805 29 we determine under which conditions of the initial payoff functions commitment has a social value and when the simultaneous move nash equilibrium is commitment robust and discuss its pareto efficiency

regionalism and conflict peace creation and peace diversion abstract we investigate the implications of preferential trade agreements ptas for interstate conflict we set up a two stage game with three competing importers where first two of the countries decide on whether to initiate war against each other and subsequently all three countries select their import tariffs we show that ptas produce both a peace creation effect and a peace diversion effect whereby they reduce the likelihood of conflict between member countries peace creation but render the eruption of war between member and non member countries more likely peace diversion this paper is the first to identify and explicitly model the peace diversion effect of ptas and is also the only one in this literature to endogenize countries terms of trade we use data from the correlates of war project to empirically test these predictions and after controlling for endogeneity we find robust evidence of both peace creation and peace diversion in relation to pta establishment

regional integration as diplomacy regional integration agreements rias are examples of second best and have an ambiguous impact on welfare contend the authors they build a model in which rias unambiguously raise welfare by correcting for externalities it assumes that trade between neighboring countries increases trust between them and reduces the likelihood of conflict the optimum intervention in that case is a subsidy on imports from the neighbor the authors show that an equivalent solution is for the neighboring countries to tax imports from the rest of the world that is to form an ria together with imposing some domestic taxes in fact security threats have moved neighboring countries to form rias examples include the creation of the european coal and steel community 1951 and the european economic community 1957 to reduce the threat of war in europe as well as various rias among developing countries the authors show among other things that 1 the optimum tariffs on imports from the rest of the world are likely to decline over time 2 deep integration implies lower optimum external tariffs if it is exogenous 3 but if deep integration is endogenous it implies higher optimum external tariffs before it occurs and lower ones thereafter and 4 enlargement of a bloc in terms of symmetric countries has an ambiguous impact on external tariffs but improves welfare and some form of domino effect exists in the sense that enlargement increases the incentive for nonmembers to seek accession although externalities associated with security matters imply that an ria may maximize welfare this model suggests that the ria is a transitory arrangement in the sense that optimum trade preferences are highest at the time the ria is formed when security is low and tend to decline over time in other words the ria s external trade policy becomes increasingly open over time as well as following deep integration

trade blocs trade flows and international conflict the relationship between foreign trade and political conflict has been a persistent source of controversy among scholars of international relations existing empirical studies of this topic have focused on the effects of trade flows on conflict but they have largely ignored the institutional context in which trade is conducted in this article we present some initial quantitative results pertaining to the influence on military disputes of preferential trading arrangements ptas a broad class of commercial institutions that includes free trade areas common markets and customs unions we argue that parties to the same pta are less prone to disputes than other states and that hostilities between pta members are less likely to occur as trade flows rise between them moreover we maintain that heightened commerce is more likely to inhibit conflict between states that belong to the same preferential grouping than between states that do not our results accord with this argument based on an analysis of the period since world war ii we find that trade flows have relatively little effect on the likelihood of disputes between states that do not participate in the same pta within ptas however there is a strong inverse relationship between commerce and conflict parties to such an arrangement are less likely to engage in hostilities than other states and the likelihood of a military dispute dips markedly as trade increases between them