Knowledge that Transforms

This paper analyzes the impact of income distribution on growth when investment in human capital is the source of growth and individuals vote over the degree of redistribution in the economy. The model has three main features. First, very different patterns of income distribution are conducive to high growth at different levels of per capita income. Second, growth is associated with an externality whereby investment in human capital by one group increases the productivity of other groups, thus potentially enabling them to invest in human capital. Third, the initial pattern of income distribution and the resulting political equilibrium are crucial in determining whether the transmission of this externality is promoted, in which case growth is enhanced, or prevented, in which case growth is stopped. Using a non-overlapping generations model with voting, I derive several empirical implications. In particular, the model implies an inverted-U relation between levels of inequality and levels of income in cross-sections, but not necessarily in time series, a result that seems consistent with a number of empirical studies.

This paper estimates an equilibrium model of stock price behaviour in which changes in exponentially de-trended dividends and prices are normally distributed and exogenous “noise traders” interact with “smart-money” investors who have constant absolute risk aversion. The model can explain the volatility and predictability of U.S. stock returns in the period 1871–1986 using either a low discount rate (4% or below) and a large constant risk discount on the stock price, or a higher discount rate (5% or above) and noise trading correlated with fundamentals. The data are not well able to distinguish between these explanations.

This paper analyzes the role of wealth distribution in macroeconomics through investment in human capital. It is shown that in the presence of credit markets' imperfections and indivisibilities in investment in human capital, the initial distribution of wealth affects aggregate output and investment both in the short and in the long run, as there are multiple steady states. This paper therefore provides an additional explanation for the persistent differences in per-capita output across countries. Furthermore, the paper shows that cross-country differences in macroeconomic adjustment to aggregate shocks can be attributed, among other factors, to differences in wealth and income distribution across countries.

This paper studies a class of information transmission processes called rumors. The distinctive features of these processes are that the information transmission takes place in such a way that the recipient does not quite know whether or not to believe the information and that the probability that someone receives the information depends on how many people already have it. Counter-intuitive comparative statics results are obtained. For example, more information and higher productivity may reduce welfare, while changing the speed with which the rumor spreads has no welfare effect.

This paper provides necessary and sufficient conditions for the existence of greatest and maximal elements of weak and strict preferences, and unifies two very different approaches used in the related literature (the convexity and acyclicity approaches). Conditions called transfer FS-convexity and transfer SS-convexity are shown to be necessary and, in conjunction with transfer closedness and transfer openness, sufficient for the existence of greatest and maximal elements of weak and strict preferences, respectively. The results require neither the continuity nor convexity of preferences and are valid for both ordered and unordered binary relations.

We use the framework of random matching games and develop a two-country model of the world economy, in which two national currencies compete and may be circulated as media of exchange. There are multiple equilibria, which differ in the areas of circulation of the two currencies. In one equilibrium, the two national currencies are circulated only locally. In another, one currency is circulated as an international currency. There is also an equilibrium in which both currencies are accepted internationally. We also find an equilibrium in which the two currencies are directly exchanged. We first characterize the existence conditions of these equilibria in terms of the relative country size and the degree of economic integration and then use an evolutionary approach to equilibrium selection to explain the evolution of the international currency as the two economies become more integrated. Some welfare implications are also discussed. For example, a country can improve its national welfare by letting its own currency circulate internationally, provided the domestic circulation is controlled for. When the total supply is fixed, however, a resulting currency shortage may reduce the national welfare.

Contrary to common belief, Savage's axioms do not imply strict stochastic dominance. Instead, they usually involve violation of that. Violations occur as soon as the range of the utility function is rich enough, e.g. contains an interval, and the probability measure is, loosely speaking, “constructive”. An example is given where all of Savage's axioms are satisfied, but still strict statewise monotonicity is violated: An agent is willing to exchange an act for another act that with certainty yields a strictly worse outcome. Thus book can be made against the agent. Weak stochastic dominance and weak statewise monotonicity are always satisfied, as well as strict stochastic dominance and strict statewise monotonicity when restricted to acts with finitely many outcomes.

Although models with factor price equalization are used frequently in both theoretical and applied research in international economics, only sufficient conditions for factor price equalization have been presented in the literature. In this paper, we present necessary and sufficient conditions for FPE under quite general assumptions about the technologies of different countries. The necessary and sufficient conditions we derive are consistent with joint production, decreasing returns to scale, and substantive differences in the technologies and endowments of different countries. Our results enable us to reconcile the classical approach and the integrated equilibrium approach to factor price equalization.

We present a model in which sectoral shocks have aggregate consequences. The model relies on irreversible investment and imperfect information to slow the adjustment of expanding industries. We show that this gradual expansion is sub-optimal.

In this paper we present empirical evidence on aggregation problems with Euler equations for consumption. Our main results are: estimates of the elasticity of intertemporal substitution for consumption are consistently lower for aggregate data than for average cohort data and the theoretical model is statistically rejected on aggregate data, not rejected on average cohort data. In trying to explain these differences we find that a major role is played by the non-linearity of the estimable equation and by omitted demographic factors (normally unobservable on aggregate data). However, even when these sources of aggregation bias are corrected for, the estimates of the elasticity of intertemporal substitution obtained from aggregate data remain lower than those obtained from average cohort data, and excess sensitivity tests reject the implications of the model. This can be explained as the result of imposing identical coefficients to cohorts who differ in preferences and/or opportunity sets.