In this paper, we look for long-run and short-run effects of fiscal deficits on economic growth in an endogenous growth model with productive public spending that may be financed by public deficit and debt. The model shows a multiplicity of long-run balanced growth paths (a high-growth and a low-growth steady state) and a possible indeterminacy of the transition path, which may be consistent with the empirical literature, which exhibits strong nonlinear responses of economic growth to fiscal deficits. Starting from the high-growth steady state, a positive impulse in the deficit ratio exerts an adverse effect on economic growth in the long run, after an initial rise. Starting from the low-growth steady state, the situation may be radically undetermined, and the effect of fiscal deficit impulses is subjected to “optimistic” or “pessimistic” views on public-debt sustainability.

Cultural variables in economic analysis have recently experienced a strong renewal. This evolution sheds a new light on the old debate between the “Beckerian model” of fertility and the “synthesis model” of fertility. In this paper, I propose a fertility model making the evolution of culture endogenous. The whole population is divided into two cultures corresponding to specific preferences for fertility. Parents decide their fertility rate and try to transmit their culture to their children. Differential fertility between cultures gives rise to an evolutionary process while differential effort to transmit the parental culture gives rise to a cultural process. The long-run distribution of preferences and the average total fertility rate both result from interactions between these processes. As a result, a fertility transition cannot appear without productivity shocks in favor of the culture that is not biased toward quantity of children. However, asymmetric productivity shocks are not always sufficient to cause a fertility transition.

This paper distinguishes two kinds of endogenous business cycle models: EBC1 models, which display dynamic indeterminacy, and EBC2 models, which display steady-state indeterminacy. Both strands of the literature have their origins in the sunspot literature that developed at the University of Pennsylvania in the 1980s. I argue that EBC1 models are part of the evolution of modern macroeconomics that has classical roots dating back to the 1920s. EBC2 models provide a microfoundation for one of the most important ideas to emerge from Keynes's (1936) General Theory of Employment, Interest and Money: that high involuntary unemployment can persist as part of the steady-state equilibrium of a market economy.

A genetic algorithm (GA) is used to model learning in a financial model similar to the Grossman–Stiglitz model. Individuals need to learn how to use a signal, how to make an inference about a signal from a market-clearing price, and whether or not a signal is worth acquiring. We provide examples in which the GA does and does not converge to the rational expectations equilibrium. Similar to earlier results, the behavior depends heavily on the rate of experimentation or mutation in the GA and the size of the risky-asset supply noise in the economy.

Conventional wisdom is that inflation makes people spend money faster, trying to get rid of it like a “hot potato,” and this is a channel through which inflation affects velocity and welfare. Monetary theory with endogenous search intensity seems ideal for studying this. However, in standard models, inflation is a tax that lowers the surplus from monetary exchange and hence reduces search effort. We replace search intensity with a free entry (participation) decision for buyers—i.e., we focus on the extensive rather than intensive margin—and prove buyers always spend their money faster when inflation increases. We also discuss welfare.

In this paper, we are motivated by the fact that little is known about the relative performance of broad and narrow Divisia monetary aggregates, and by recent work that tests and rejects the appropriateness of the aggregation assumptions that underlie the various monetary aggregates published by the Federal Reserve as well as a large number of monetary asset groupings suggested by earlier studies. We present a comprehensive comparison of narrow versus broad Divisia monetary aggregates within three classes of empirical models. We compute correlations between the cyclical components of Divisia monetary aggregates at different levels of aggregation and the cyclical component of industrial production. We test for Granger causality running from the Divisia aggregates to industrial production and various other measures of real economic activity. We also reestimate a structural vector autoregression based on earlier work by Leeper and Roush [(2003) Journal of Money, Credit, and Banking 35, 1217–1256] and Belongia and Ireland [(2015) Journal of Business and Economic Statistics 33, 255–269; (2016) Journal of Money, Credit and Banking 48, 1223–1266], modifying that earlier work using monthly rather than quarterly data and extending it, both using broad as well as narrower Divisia monetary aggregates and by allowing for Generalized autoregressive conditional heteroskedasticity (GARCH) behavior in the structural shocks.

We investigate the effects of memory on the stability of evolutionary selection dynamics based on a multinomial logit model in a simple asset pricing model with heterogeneous beliefs. Whether memory is stabilizing or destabilizing depends in general on three key factors: (1) whether or not the weights on past observations are normalized; (2) the ecology or composition of forecasting rules, in particular the average trend extrapolation factor and the spread or diversity in biased forecasts; and (3) whether or not costs for information gathering of economic fundamentals have to be incurred.

Oil prices rose sharply prior to the onset of the 2007–2009 recession. Hamilton [in the Palgrave Dictionary of Macroeconomics (2008)] noted that nine of the last ten recessions in the United States were preceded by a substantial increases in the price of oil. In this paper, we consider whether oil price shocks significantly increase the probability of recessions in a number of countries. Because business cycle turning points generally are not available for other countries, we estimate the turning points together with oil's effect in a Markov-switching model with time-varying transition probabilities. We find that, for most countries, oil shocks do affect the likelihood of entering a recession. In particular, for a constant, zero-term spread, an average-sized shock to WTI oil prices increases the probability of recession in the United States by nearly 50 percentage points after one year and nearly 90 percentage points after two years.

Who is Robert Aumann? Is he an economist or a mathematician? A rational scientist or a deeply religious man? A deep thinker or an easygoing person?

These seemingly disparate qualities can all be found in Aumann; all are essential facets of his personality. A pure mathematician who is a renowned economist, he has been a central figure in developing game theory and establishing its key role in modern economics. He has shaped the field through his fundamental and pioneering work, work that is conceptually profound, and much of it also mathematically deep. He has greatly influenced and inspired many people: his students, collaborators, colleagues, and anyone who has been excited by reading his papers or listening to his talks.

Aumann promotes a unified view of rational behavior, in many different disciplines: chiefly economics, but also political science, biology, computer science, and more. He has broken new ground in many areas, the most notable being perfect competition, repeated games, correlated equilibrium, interactive knowledge and rationality, and coalitions and cooperation.

But Aumann is not just a theoretical scholar, closed in his ivory tower. He is interested in real-life phenomena and issues, to which he applies insights from his research. He is a devoutly religious man; and he is one of the founding fathers—and a central and most active member—of the multidisciplinary Center for the Study of Rationality at the Hebrew University in Jerusalem.

Aumann enjoys skiing, mountain climbing, and cooking—no less than working out a complex economic question or proving a deep theorem. He is a family man, a very warm and gracious person—of an extremely subtle and sharp mind.

This interview catches a few glimpses of Robert Aumann's fascinating world. It was held in Jerusalem on three consecutive days in September 2004. I hope the reader will learn from it and enjoy it as much as we two did.

Economic theory indicates the need for nonlinear structural models to study medium-term and long-run dynamic behavior of an economy. This paper argues that economic systems can be better specified and estimated using differential-equation rather than difference-equation systems and briefly reviews the estimators of continuous models. This approach of specifying structural models on the basis of economic theory and institutional structure explicitly and then testing the underlying hypothesis to verify the structural form is contrasted with a general-to-specific approach of successively more restricted VARMAX processes. Previous analyses of stability about the steady state or fixed point in phase space are extended to more general attractors to allow an investigation of complexity in economic systems. The critical dependence of some attractors, and particularly strange attractors, on parameter values emphasizes the need for consistent, efficient estimation. A structural approach provides a rigorous alternative to using single time series to determine whether economic systems exhibit aperiodic or chaotic dynamical behavior.

This paper presents a new framework for analyzing inequality that moves beyond the anonymity postulate. We estimate the determinants of sectoral choice and the joint distributions of outcomes across sectors. We determine which components of realized earnings variability are due to uncertainty and which components are due to components of human diversity that are forcastable by agents. Using our tools, we can determine how policies shift persons across sectors and outcome distributions across sectors.

We develop an overlapping-generations model for a closed economy with uncertainty on labor income and mortality risk to show that unfunded social security programs may increase welfare in economies where agents are affected by self-control problems à la Gul and Pesendorfer (2001, Econometrica 69, 1403). We depart from the existing literature by setting the agent's preference parameters to match target levels of macro-variables observed in the real U.S. economy. In our approach, economies with tempted and nontempted agents are indistinguishable in terms of aggregate consumption, labor, and saving behavior when social security provides a replacement rate of 40% (as in the United States). This situation makes agents bear costly self-control problems over more years. Our simulations indicate that social security improves welfare with degrees of temptation equal to 11% or higher. A social security program with a replacement rate of 40% finds support for degrees of temptation not lower than 15%.

We use an agent-based computational approach to show how inflation can worsen macroeconomic performance by disrupting the mechanism of exchange in a decentralized market economy. We find that, in our model economy, increasing the trend rate of inflation above 3% has a substantial deleterious effect, but lowering it below 3% has no significant macroeconomic consequences. Our finding remains qualitatively robust to changes in parameter values and to modifications to our model that partly address the Lucas critique. Finally, we contribute a novel explanation for why cross-country regressions may fail to detect a significant negative effect of trend inflation on output even when such an effect exists in reality.

Our intention is to study, in the framework of a very simple optimal growth model, the consequences on the optimal paths followed by consumption and the environmental quality of an endogenous discounting. Consumption directly comes from the use of environmental services and so is a direct cause of environmental degradation. The environment is valued both as a source of consumption and as an amenity. For a sustainability concern, we introduce an endogenous discount rate growing with the environmental quality, and compare the optimal growth paths with the ones obtained in the usual case of exogenous and constant discounting. We show that the convergence of the environmental quality toward a steady state occurs only for a very special configuration of the parameters in the exogenous discounting case, whereas it occurs generically in the endogenous discounting one. This happens for a utility discount rate becoming sufficiently high when the environmental quality is high and sufficiently low when the environmental quality is poor. In this case, then, endogenous discounting with a positive marginal discount rate allows us to avoid the depletion of the environment.

Recent research shows that when commonly estimated dynamic Taylor rules, which are augmented with a lagged interest, are embedded in a variety of macroeconomic models, they imply a greater amount of predictable information about future movements in interest rates than is actually evident in the yield curve. We extend the analysis to consider more generally the predictability of the arguments of the Taylor rule—inflation and the output gap—in addition to the interest rate. Specifically, we compare the predictability of these three variables in a macroeconomic model with a dynamic Taylor rule to their predictability in real-time surveys of macroeconomic forecasters or a VAR model. We find that the strongest evidence against the dynamic Taylor rule is that while it is easy to predict the variables that enter the rule, it is very hard to predict actual interest rate changes. This disparity suggests that dynamic Taylor rules neglect important aspects of monetary policy behavior.

In this paper, we investigate the impact of globalization on wages earned by low- and high-skill workers when openness leads to the outsourcing of high-tech jobs abroad. We have shown that low-skill workers may become considerably better off after globalization because high-skill workers start accepting low-tech jobs. The switch in the behavior of high-skill workers brings about general equilibrium responses from the firm side of the labor market with the outside options for low-skill workers improving significantly. This feedback works as a magnification mechanism that leads to a discontinuous wage increase that one would not be able to get without careful modeling of the frictions in the labor market.

This paper examines the quantitative implications of government fiscal policy in a discrete-time one-sector growth model with a productive externality that generates social increasing returns to scale. Starting from a laissez-faire economy that exhibits local indeterminacy, we show that the introduction of a constant capital tax or subsidy can lead to various forms of endogenous fluctuations, including stable 2-, 4-, 8-, and 10-cycles, quasiperiodic orbits, and chaos. In contrast, a constant labor tax or subsidy has no effect on the qualitative nature of the model's dynamics. We show that the use of local steady-state analysis to detect the presence of multiple equilibria in this class of models can be misleading. For a plausible range of capital tax rates, the log-linearized dynamical system exhibits saddle-point stability, suggesting a unique equilibrium, whereas the true nonlinear model exhibits global indeterminacy. This result implies that stabilization policies designed to suppress sunspot fluctuations near the steady state may not prevent sunspots, cycles, or chaos in regions away from the steady state. Overall, our results highlight the importance of using a model's nonlinear equilibrium conditions to fully investigate global dynamics.

This study develops a Schumpeterian growth model to analyze the effects of different patent instruments on innovation. We first analyze patent breadth, which captures the traditional positive effect of patent rights on innovation. Then, we consider a profit-division rule between entrants and incumbents. Given the division of profit, increasing the share of profit assigned to incumbents reduces entrants' incentives for innovation. This aspect of blocking patents captures the recently proposed negative effect of patent rights on innovation. Finally, blocking patents generate a nonmonotonic effect on innovation when the step size of innovation is endogenous because of a novel escape-infringement effect. Calibrating the model to aggregate data, we find that a marginal increase in the blocking effect of patent protection is likely to enhance economic growth.

This paper focuses on the macroeconomic and wealth effects of unconventional monetary policy. To this end, we estimate a Bayesian structural vector autoregression (B-SVAR) using U.S. monthly data for the post-Lehman Brothers' collapse period. We show that a positive shock to the growth rate of central bank reserves does not have a substantial impact on industrial production or consumer prices. However, it also gives a strong boost to asset prices, which is larger in magnitude for stock prices than for housing prices. Thus, unconventional monetary policy typically operates via portfolio-rebalancing effects. A VAR counterfactual exercise confirms the role of the shocks to the growth rate of central bank reserves in explaining the dynamics of the variables included in the system, especially in the case of asset prices. Finally, additional empirical assessments uncover an important change in the conduct of monetary policy from “standard” to “exceptional” times and the suitability of our model to capture such a structural transformation.

We study the impact of a minimum consumption requirement on the rate of economic growth and the evolution of wealth distribution. The requirement introduces a positive dependence between the intertemporal elasticity of substitution and household wealth. This dependence implies a transition phase during which the growth rate of per-capita quantities rise toward their steady-state values and the distributions of wealth, consumption, and permanent income become more unequal. We calibrate the minimum consumption requirement to match estimates available for a sample of Indian villagers and find that these transitional effects are quantitatively significant and depend importantly on the economy's steady-state growth rate.