Research Database

This paper develops a dynamic general equilibrium model of economic growth. The model has a steady state equilibrium in which some firms devote resources to discovering qualitatively improved products and other firms devote resources to copying these products. Rates of both innovation and imitation are endogenously determined based on the outcomes of R&D races between firms. Innovation subsidies are shown to unambiguously promote economic growth. Welfare is only enhanced however if the steady state intensity of innovative effort exceeds a critical level.

The paper proposes a theory of ambiguous financial contracts. Leaving contractual contingencies unspecified may be optimal, even when stipulating them is costless. We show that an ambiguous contract has two advantages. First, it permits the guarantor to sacrifice reputational capital in order to preserve financial capital as well as information reusability in states where such tradeoff is optimal. Second, it fosters the development of reputation. This theory is then used to explain ambiguity in mutual fund contracts, bank loan commitments, bank holding company relationships, the investment banker's "highly confident" letter, non-recourse debt contracts in project financing, and other financial contracts.

This paper proposes a model of diversifiable uncertainty, irreversible investment decisions, and endogenous growth. The detailed microeconomic structure of the model makes it possible to study the. general equilibrium effects of obstacles to labor mobility, due to institutional as well as technological features of the economy. Labor mobility costs reduce private returns to investment, and the resulting slower rate of endogenous growth unambiguously lowers a representative individual's welfare. Turnover costs can have positive effects on full employment equilibrium wages when all external effects are disregarded: this may help explain why policy and institutions often tend to decrease labor mobility in reality, rather than to enhance it. Lower flexibility, however, reduces the growth rate of wages in endogenous growth equilibrium, with negative welfare effects even for agents who own only labor.

How much technological progress has there been in structures? An attempt is made to measure this using panel data on the age and rents for buildings. This data is interpreted through the eyes of a vintage capital model where buildings are replaced at some chosen periodicity. There appears to have been significant technological advance in structures that accounts for a major part of economic growth.

Procedures for computing the parameters of a broad class of multifactor continuous time models of the term structure based on indirect estimation methods are proposed. The approach consists of simulating the unknown factors from a set of stochastic differential equations which are used to compute synthetic bond yields. The bond yields are calibrated with actual bond yields via an auxiliary model. The approach circumvents many of the difficulties associated with direct estimation of this class of models using maximum likelihood. In particular, the paper addresses the identification issues arising from singularities in the yields and spreads which tend not to be recognised in existing estimation procedures and thereby overcome potential misspecification problems inherrent in direct methods. Indirect estimates of single and multifactor models are computed and compared with the estimates based on existing estimation procedures.

This paper examines the determination of the rate of growth in an economy in which two political parties, each representing a different social class, negotiate the magnitude and allocation of taxes. Taxes may increase growth if they finance public services, but reduce growth when used to redistribute income between classes. The different social classes have different preferences about growth and redistribution. The resulting conflict is resolved through the tax negotiations between the political parties. I use the model to obtain empirical predictions and policy lessons about the relationship between economic growth and income inequality. In particular, I show that, although differences in growth rates across countries may be negatively related to income inequality, redistributing wealth does not enhance growth.

The possibility of exact maximum likelihood estimation of many observation-driven models remains an open question. Often only approximate maximum likelihood estimation is attempted, because the unconditional density needed for exact estimation is not known in closed form. Using simulation and nonparametric density estimation techniques that facilitate empirical likelihood evaluation, we develop an exact maximum likelihood procedure. We provide an illustrative application to the estimation of ARCH models, in which we compare the sampling properties of the exact estimator to those of several competitors. We find that, especially in situations of small samples and high persistence, efficiency gains are obtained.

Some economic policies and regulations seem to have only one purpose: to prevent technological development and economic growth from occurring. In this paper, we attempt to rationalize such policies as outcomes of voting equilibria. In our environment, some agents will be worse off if the economy grows, since their skills are complementary to resources that can be allocated to growth-stimulating activities. In the absence of arrangements where votes are traded, we show that for some initial skill distributions, the economy may stagnate due to growth-preventing policies. Different initial skill distributions, however, lead to voting outcomes and policies in support of technological development, and to persistent economic growth. In making our argument formally, we use a dynamic model with induced heterogeneity in agents' skills. In their voting decisions, agents compare how they will be affected under each policy alternative, and then vote for the policy that maximizes their welfare.

In this paper we study the relationship between wealth, income distribution and growth in a game-theoretic context in which property rights are not completely enforcable. We consider equilibrium paths of accumulation which yield players utilities that are at least as high as those that they could obtain by appropriating higher consumption at the present and suffering retaliation later on. We focus on those subgame perfect equilibria which are constrained Pareto-efficient (second best). In this set of equilibria we study how the level of wealth affects growth. In particular we consider cases which produce classical traps (with standard concave technologies): growth may not be possible from low levels of wealth because of incentive constraints while policies (sometimes even first-best policies) that lead to growth are sustainable as equilibria from high levels of wealth. We also study cases which we classify as the "Mancur Olson" type: first best policies are used at low levels of wealth along these constrained Pareto efficient equilibria, but first best policies are not sustainable at higher levels of wealth where growth slows down. We also consider the unequal weighting of players to ace the subgame perfect equiliria on the constrained Pareto frontier. We explore the relation between sustainable growth rates and the level of inequality in the distribution of income.

We introduce, into a version of the Real Business Cycle model, mild increasing returns-to-scale. These increasing returns-to-scale occur as a consequence of sector specific externalities, that is externalities where the output of the consumption and investment sectors have external effects on the output of firms within their own sector. Keeping the production technologies for both sectors identical for expositional simplicity, we show that indeterminacy can easily occur for parameter values typically used in the real business cycle literature, and in contrast to some earlier literature on indeterminacies, for externalities mild enough so that labor demand curves are downward sloping.

This paper develops the Kiyotaki-Wright model of monetary general equilibrium in which trade is bilateral and enforced by requiring that transactions be quid pro quo, and studies which goods are chosen, and under what conditions, as media of exchange. We prove the existence of a rational expectations equilibrium in which agents' expectations concerning trading opportunities are realized in the present and all future periods. We also show that, exceptional cases aside, no rational expectations barter equilibrium exists; that an equilibrium generally supports multiple money goods; and that a fiat money (i.e., a good that is produced, has minimum storage costs, but is not consumed) cannot be traded in rational expectations equilibrium.