Voracity, growth, and welfare

This paper explores some implications of the comparison between feedback Nash and Stackelberg equilibria for growth and welfare in a ‘voracity’ model. We show that, as compared to the Nash equilibrium, the Stackelberg equilibrium involves a lower growth rate, while it leaves both the leaders and the followers better off, i.e., the Stackelberg equilibrium is Pareto superior to the Nash equilibrium.     

Public infrastructure,non‐cooperative investments,and endogenous growth

Two countries strategically invest in productive infrastructure within a general equilibrium model with endogenous growth. These public investments generate externalities. Dynamic analysis reveals that: (1) under constant returns, the two countries’ growth rates differ during the transition but are identical on the balanced growth path, (2) a country with decreasing returns can experience sustained growth provided that the other country grows at a positive constant rate, (3) cooperation does not necessarily lead to higher growth for each country, and it can increase or decrease the gap between countries’ growth rates depending on the countries’ consumption preferences regarding domestic and foreign goods.     

Strategic analysis of petty corruption: Entrepreneurs and bureaucrats

This paper develops a game-theoretic model of “petty corruption” by government officials. Such corruption is widespread, especially (but not only) in developing and transition economies. The model goes beyond the previously published studies in the way it describes the structure of bureaucratic “tracks,” and the information among the participants. Entrepreneurs apply, in sequence, to a “track” of two or more bureaucrats in a prescribed order for approval of their projects. Our first result establishes that in a one-shot situation no project ever gets approved. This result leads us to consider a repeated interaction setting. In that context we characterize in more detail the trigger-strategy equilibria that minimize the social loss due to the system of bribes, and those that maximize the expected total bribe income of the bureaucrats. The results are used to shed some light on two much advocated anti-corruption policies: the single window policy and rotation of bureaucrats.     

Resource-grabbing by status-conscious agents

We introduce a dynamic model of resource-grabbing by status-conscious agents, i.e., agents value not only their absolute consumption levels, but also the relative status within their reference group. We explore the effect of the concern for relative consumption on the growth rate and the welfare of an economy where agents appropriate from a common property resource. Our model shows that the greater is agents' concern about their relative status, the more aggressively they tend to behave. Consequently, social welfare is lower because the growth rate of the public asset is reduced due to higher extraction rate. We also consider the effect of increased heterogeneity, and show that social welfare decreases as the distribution of status-consciousness among agents widens.     

Public goods in directed networks

We study the provision of a public good in a social network where links are directed, i.e., the information flows one way. Our results relate, through stochastic dominance, the equilibrium outcome of such a process with the out-degree distribution of the network.     

Interlinkage and Generous Tit‐for‐Tat Strategy

We investigate an infinitely‐repeated prisoners' dilemma with imperfect monitoring and consider the possibility that the interlinkage of the players' distinct activities enhances implicit collusion. We show a necessary and sufficient condition for the existence of a generous tit‐for‐tat Nash equilibrium. Such an equilibrium, if it exists, is unique. This equilibrium achieves approximate efficiency when monitoring is almost perfect, where the discount factors are fixed.     

Strategic intergenerational bequests with stochastic convex production

Summary This note reconsiders the well-known model of strategic bequest/ altruistic growth, but with stochastic production satisfying a strong convexity condition: The probability that the next stock exceeds any given level is concave in investment. Existence of a Markov-stationary equilibrium consumption schedule, which is continuous and with all slopes in [0,1], is established. Under smooth data and interiority assumptions, this schedule is differentiable, and marginal consumption is in (0,1). This property allows for a rigorous and straightforward treatment of the equilibrium characterization problem.The author is grateful to Wolfgang Leininger for helpful discussions on the subject of this paper. This research work was carried out while the author was visiting C.O.R.E., Belgium and the University of Dortmund, Germany. The author wishes to thank both institutions for providing a great work environment as well as financial support from the projects Markets as Games and Marktstruktut und Gesamtwirtschaftliche Entwicklung, respectively.     

A nonsmooth, nonconvex model of optimal growth

This paper analyzes the nature of economic dynamics in a one-sector optimal growth model in which the technology is generally nonconvex, nondifferentiable, and discontinuous. The model also allows for irreversible investment and unbounded growth. We develop various tools to overcome the technical difficulties posed by the generality of the model. We provide sufficient conditions for optimal paths to be bounded, to converge to zero, to be bounded away from zero, and to grow unboundedly. We also show that under certain conditions, if the discount factor is close to 1, any optimal path from a given initial capital stock converges to a small neighborhood of the golden rule capital stock, at which sustainable consumption is maximized. If it is maximized at infinity, then as the discount factor approaches 1, any optimal path either grows unboundedly or converges to an arbitrarily large capital stock.     

Asymmetry, stability and growth in a step-by-step R&D-race

We define a notion of stability of equilibrium in an infinitely repeated step-by-step R&D race. The unique symmetric equilibrium is shown to be unstable, and stable asymmetric equilibria arise, if product market competition is intense, firms are patient, imitation is difficult and innovations are large. Some predictions based on symmetric equilibria, e.g. that less patient firms always invest less in research, or that more intensive competition leads to higher economic growth, are reversed for “realistic” values of the underlying parameters.     

The contracting value of tainted reports in cost reduction settings

While cost accounting is a well-developed discipline with a rich institutional past, it is criticized for being manipulable. This criticism is due, in part, to the existence of multiple, yet equally accepted cost allocation procedures or cost estimation techniques. Employing a principal-agent model, cost accounting is modeled as a menu of alternative methods which, conditional on agent effort, produce noisy, unbiased and independently distributed (i.e., equally defensible) measures from which a single realization is selected ex post as the report used to contract with the agent. Assuming that the report does not indicate which method produced it, the report modeled is “tainted” in that the lowest (most favorable to the agent) outcome is reported, where the “amount” of tainting corresponds to the menu's size. The paper identifies bright-line conditions where the principal's expected net payoff is independent of the amount of tainting, demonstrating that tainting does not necessarily affect the report's incentive value.     

R&D INCENTIVES UNDER BERTRAND COMPETITION: A DIFFERENTIAL GAME*

We investigate dynamic R&D for process innovation in an oligopoly where firms invest in cost‐reducing activities. We focus on the correlation between R&D intensity and market structure, proving that the industry R&D investment at equilibrium monotonically increases in the number of firms. This result contradicts the established wisdom acquired from static games on the same topic. We also prove that, if competition is sufficiently tough, any increase in product substitutability reduces R&D efforts.     

On the endogeneity of Cournot-Nash and Stackelberg equilibria: games of accumulation

We characterize equilibria of games with two properties: (i) Agents have the opportunity to adjust their strategic variable after their initial choices and before payoffs occur; but (ii) they can only add to their initial amounts. The equilibrium set consists of just the Cournot-Nash outcome, one or both Stackelberg outcomes, or a continuum of points including the Cournot-Nash outcome and one or both Stackelberg outcomes. A simple theorem that uses agents’ standard one-period reaction functions and the one-period Cournot-Nash and Stackelberg equilibria delineates the equilibrium set. Applications include contribution, oligopoly, and rent-seeking games.     

STRATEGIC INTERACTION AND CATCHING UP

In this study, we prove that the strategic interaction among agents differing in initial wealth levels leads the poor to be able to catch up with the rich, which is not the case for the standard Ramsey model where the initial wealth differences perpetuate. Extending the analysis to account for relative wealth concern and the adjustment cost of consumption, the strategic interaction among agents is shown to affect not only the distribution of wealth in the long run but also the transitional dynamics substantially. In particular, we show that structurally very simple frameworks may lead to limit cycles thanks to the strategic interaction among agents in the economy.     

Competitive experimentation with private information: The survivor's curse

We study a winner-take-all R&D race between two firms that are privately informed about the arrival rate of an invention. Over time, each firm only observes whether the opponent left the race or not. The equilibrium displays a strong herding effect, that we call a ‘survivor's curse.’ Unlike in the case of symmetric information, the two firms may quit the race (nearly) simultaneously even when their costs and benefits for research differ significantly.     

Asymmetric Information,Auditing Commitment,and Economic Growth

We analyze in this paper the growth and welfare consequences stemming from the lack of auditing commitment in a credit market with costly state verification. By studying two endogenous growth models, one of which allows lenders to commit to costly auditing strategies, whereas the other does not, we show that the inability to commit serves as a source of informational friction that results in more stringent contractual terms, which, in turn, result in lower capital accumulation, growth, and welfare. From the policy perspective, our analysis suggests a new micro‐economic channel through which institutional failings hinder economic growth and social welfare.     

Investment dynamics with common and private values

We study a dynamic investment game with two-dimensional signals, where each firm observes its continuously distributed idiosyncratic cost of investment and a discrete signal correlated with common investment returns. We demonstrate that the one-step property holds and provide an equilibrium existence/characterization result. “Reversals” are possible, where a large number of firms investing in a given round becomes bad news about investment returns. Welfare is compared to static and rigid-timing benchmarks, and computed for large economies.     

Preemption in a real option game with a first mover advantage and player-specific uncertainty

In this paper a two-player real option game with a first-mover advantage is analyzed, where payoffs are driven by a player-specific stochastic state variable. It is shown that there exists an equilibrium which has qualitatively different properties from those in standard real option games driven by common stochastic shocks. The properties of the equilibrium are four-fold: (i) preemption does not necessarily occur, (ii) if preemption takes place, the rent-equalization property holds, (iii) for almost all sample paths it is clear ex-ante which player invests first, and (iv) it is possible that both players invest simultaneously, even if that is not optimal. It is argued from simulations that real option games with a common one-dimensional shock do not provide a good approximation for games with player-specific uncertainty, even if these are highly correlated.