Continuous Stochastic Games of Capital Accumulation with Convex Transitions

We consider a discounted stochastic game of common-property capital accumulation with nonsymmetric players, bounded one-period extraction capacities, and a transition law satisfying a general strong convexity condition. We show that the infinite-horizon problem has a Markov-stationary (subgame-perfect) equilibrium and that every finite-horizon truncation has auniqueMarkovian equilibrium, both in consumption functions which arecontinuous and nondecreasingand have all slopes bounded above by 1. Unlike previous results in strategic dynamic models, these properties are reminiscent of the corresponding optimal growth model.Journal of Economic LiteratureClassification Codes: C73, O41, Q20.     

On strategic complementarity conditions in Bertrand oligopoly

Summary. For Bertrand duopoly with linear costs, we establish via a single (counter-)example that: (i) A new monotone transformation of the firms' profit functions may lead to the supermodularity of transformed profits when the standard log and identity transformations both fail to do so, and (ii) Topkis's notion of critical sufficient condition for monotonicity of a Bertrand firm's best-reply correspondence cannot be extended to rely only on positive unit costs. Received: January 16, 2001; revised version: March 20, 2002 RID="*" ID="*" This work was completed while the first author was visiting the Institute for Industrial Economics at the University of Copenhagen during Spring 2000. Their financial support and stimulating research environment are gratefully acknowledged. The views expressed here are those of the authors and should not be attributed to the European Commission. Correspondence to: R. Amir     

Free Trade versus Autarky under Asymmetric Cournot Oligopoly

The paper compares free trade with autarky in an asymmetric multi‐country world under Cournot competition with constant returns to scale and linear demand. We derive respective conditions under which free trade will hurt a country's consumers, benefit its firms, induce it to export, increase its output and raise its welfare. We show that these conditions are linked in a clear order, with one implying the next. We further demonstrate that free trade can reduce world total output and total consumer surplus as well as world welfare. Along the way, we correct several oversights in the literature.     

Global Imbalances and Petrodollars

Oil exporters have run large current account surpluses. We explore oil exporters’ role in the global imbalances debate. Current account dynamics are estimated for oil‐exporting countries and the rest of the world. We find that fiscal policy has a much stronger effect on the current account of oil exporters than on current accounts of other countries. The current account adjustment of oil‐exporting countries is also faster. Fiscal policy of oil exporters can have a significant and speedy impact on global imbalances. The impact via the adjustment of exchange rates might not be effective.     

Production planning and inventories optimization: A backward approach in the convex storage cost case

We study the deterministic optimization problem of a profit-maximizing firm which plans its sales/production schedule. The firm controls both its production and sales rates and knows the revenue associated to a given level of sales, as well as its production and storage costs. The revenue and the production cost are assumed to be respectively concave and convex. In Chazal et al. [Chazal, M., Jouini, E., Tahraoui, R., 2003. Production planning and inventories optimization with a general storage cost function. Nonlinear Analysis 54, 1365–1395], we provide an existence result and derive some necessary conditions of optimality. Here, we further assume that the storage cost is convex. This allows us to relate the optimal planning problem to the study of a backward integro-differential equation, from which we obtain an explicit construction of the optimal plan.     

Asset market games of survival: a synthesis of evolutionary and dynamic games

The paper examines a game-theoretic model of a financial market in which asset prices are determined endogenously in terms of a short-run equilibrium. Investors use general, adaptive strategies (portfolio rules) depending on the exogenous states of the world and the observed history of the game. The main goal is to identify portfolio rules, allowing an investor to “survive,” i.e., to possess a positive, bounded away from zero, share of market wealth over an infinite time horizon. The model under consideration combines a strategic framework characteristic for stochastic dynamic games with an evolutionary solution concept (survival strategies), thereby linking two fundamental paradigms of game theory.     

Cooperation vs. competition in R&D: The role of stability of equilibrium

We consider a model in which firms first choose process R&D expenditures and then compete in an output market. We show the symmetric equilibrium under R&D competition is sometimes unstable, in which case two asymmetric equilibria must also exist. For the latter, we find, in contrast to the literature that total profits are sometimes higher with R&D competition than with research joint venture cartelization (due to the cost asymmetry of the resulting duopoly in the noncooperative case). Furthermore, these equilibria provide another instance of R&D-induced firm heterogeneity.     

On Environmental Regulation of Oligopoly Markets: Emission versus Performance Standards

By specializing Montero’s (J Environ Econ Manag 44:23–44, 2002) model of environmental regulation under Cournot competition to an oligopoly with linear demand and quadratic abatement costs, we extend his comparison of firms incentives to invest in R&D under emission and performance standards by solving for a closed form solution of the underlying two-stage game. This allows for a full comparison of the two instruments in terms of their resulting propensity for R&D and equilibrium industry output. In addition, we incorporate an equilibrium welfare analysis. Finally, we investigate a three-stage game wherein a welfare-maximizing regulator sets a socially optimal emission cap under each policy instrument. For the latter game, while closed-form solutions for the subgame-perfect equilibrium are not possible, we establish numerically that the resulting welfare is always larger under a performance standard.     

On the Effects of Entry in Cournot Markets

In the framework of symmetric Cournot oligopoly, this paper provides two minimal sets of assumptions on the demand and cost functions that imply respectively that, as the number of firms increases, the minimal and maximal equilibria lead to (i) decreasing industry price and increasing or decreasing per-firm output; and (ii) increasing industry price (and decreasing per firm output.) In both cases, per-firm profits are decreasing.
The analysis relies crucially on lattice-theoretic methods and yields general, unambiguous and easily interpretable conclusions of a global nature. As a byproduct of independent interest, new insight into the existence of Cournot equilibrium is developed.     

Commodity windfalls,polarization, and net foreign assets: Panel data evidence on the voracity effect

This paper examines the effects that windfalls from international commodity price booms have on net foreign assets in a panel of 145 countries during the period 1970–2007. The main finding is that windfalls from international commodity price booms lead to a significant increase in net foreign assets, but only in countries that are ethnically homogeneous. In highly ethnically polarized countries, net foreign assets significantly decreased. To explain this asymmetry, the paper shows that in ethnically polarized countries commodity windfalls lead to large increases in government consumption expenditures and political corruption. The paper's findings are consistent with theoretical models of the current account that have a built-in voracity effect.