In one-sector neoclassical growth models, consumption externalities lead to an inefficient allocation in a steady state and indeterminate equilibrium toward a steady state only if there is a labor–leisure trade-off. This paper shows that in a two-sector neoclassical growth model, even without a labor–leisure trade-off, consumption spillovers easily lead to an inefficient allocation in a steady state and indeterminate equilibrium toward a steady state. Negative consumption spillovers that yield ove-accumulation of capital in a one-sector model may lead to underaccumulation or overaccumulation of capital in two-sector models, depending on the relative capital intensity between sectors. Moreover, a two-sector model economy with consumption externalities is less stabilized than an otherwise identical one-sector model economy.

We analyze the forecasting performance of small mixed-frequency factor models when the observed variables share stochastic trends. The indicators are observed at various frequencies and are tied together by cointegration so that valuable high-frequency information is passed to low-frequency series through the common factors. Differencing the data breaks the cointegrating link among the series and some of the signal leaks out to the idiosyncratic components, which do not contribute to the transfer of information among indicators. We find that allowing for common trends improves forecasting performance over a stationary factor model based on differenced data. The “common-trends factor model” outperforms the stationary factor model at all analyzed forecast horizons. Our results demonstrate that when mixed-frequency variables are cointegrated, modeling common stochastic trends improves forecasts.

This paper develops a general equilibrium model with a banking system and a reserves market and shows that (i) the macroeconomic stabilizing properties of the nominal interest rate rules change quite substantially when we move from a model without a banking system to one with a banking system and a reserves market; (ii) the interplay between fiscal and monetary policies, in particular inflation-indexed versus non-indexed bonds, is crucial in determining the macroeconomic stabilizing properties of monetary rules; (iii) active rules and passive rules perform equally in regard to their macroeconomic stabilizing properties; (iv) continuous- and discrete-time specifications deliver the same/different (in)determinacy results for both the labor-only model and the endogenous-capital model under forward-looking/current-looking rules; (v) the inclusion of physical investment narrows the indeterminacy region under forward-looking rules; and (vi) current-looking rules make equilibrium determinacy impossible for both the labor-only economy and the endogenous-capital economy. Economic intuitions are provided.

This paper proposes an unobserved-component approach to estimate expected returns on household assets and expected growth rates of excess consumption (consumption in excess of labor income) within a present-value model of consumption. The present-value model of consumption implies that the excess-consumption–assets ratio can be expressed as a function of the present discounted value of expected excess-consumption growth rate and expected asset returns. Because expected returns and expected excess-consumption growth rate are unobserved variables, we use an unobserved-component approach to extract them from the observed history of realized returns and excess-consumption growth rate. Our results suggest that both filtered returns and filtered excess-consumption growth rate are significant and better predictors of realized returns and realized excess-consumption growth rate than the one obtained by the lagged excess-consumption–assets ratio.

Estimated microproduction functions confront two major problems—those of (1) unknown functional forms and (2) the measurement of capital independent of the distribution of output among the factors of production. The latter problem has emerged unresolved from the earlier Cambridge capital controversy. In the presence of these two problems, all specifications of microproduction functions have involved nonunique coefficients and error terms. We provide a method of deriving time-varying coefficients that produces unique coefficients and error terms. Specifically, we respecify the microproduction function in such a way that its coefficients are the sums of (i) the appropriate partial derivatives and (ii) exact representations of excluded-variable biases. By decomposing the total coefficients, we obtain the unique coefficients and a unique error term. Our treatment of heterogeneous capital is not subject to the criticisms of that concept that emerged during the Cambridge controversy.

A well-documented property of the Beveridge–Nelson trend–cycle decomposition is the perfect negative correlation between trend and cycle innovations. We show how this may be consistent with a structural model where permanent innovations enter the cycle or transitory innovations enter the trend, and that identification restrictions are necessary to make this structural distinction. A reduced-form unrestricted version is compatible with either option, but cannot distinguish which is relevant. We discuss economic interpretations and implications using U.S. real GDP data.

The ideas production function is at the heart of endogenous growth theory. Using data for Europe, its offshoots, and the Asian Tiger economies over the period from 1870 to 2010, this paper provides direct estimates of an ideas production function that explicitly distinguishes between the first- and second-generation endogenous growth models while allowing for human capital and international knowledge spillovers through various channels. The estimates show strong intertemporal and cross-country knowledge spillovers, provide robust support for Schumpeterian growth theory, and suggest that human capital and some channels of international knowledge spillover are influential for ideas production.

This paper is an up-to-date survey of the state of the art in dynamical systems theory relevant to high levels of dynamical complexity, characterizing chaos and near-chaos, as commonly found in the physical sciences. The paper also surveys applications in economics and finance. This survey does not include bifurcation analyses at lower levels of dynamical complexity, such as Hopf and transcritical bifurcations, which arise closer to the stable region of the parameter space. We discuss the geometric approach (based on the theory of differential/difference equations) to dynamical systems and make the basic notions of complexity, chaos, and other related concepts precise, having in mind their (actual or potential) applications to economically motivated questions. We also introduce specific applications in microeconomics, macroeconomics, and finance and discuss the policy relevance of chaos.

This paper investigates the international dimension of economic fluctuations and transmission of structural shocks by estimating a structural VAR model for the United States, the euro area, and Japan—the three largest economies—over the post-Bretton Woods period. The main findings are as follows: (1) Supply-side shocks (technology and supply-level shocks) explain most of the fluctuations in cross-country output deviations. (2) Real-demand shocks are the most important source of real-exchange-rate fluctuations. (3) Current account is usually influenced by all types of shocks, with technology shocks playing a stronger role. In particular, technology shocks play a prominent role in the existing global imbalance (the large external deficit of the United States). (4) Technology and supply-level shocks generate opposite-signed correlations between output differential and current account, whereas real and nominal-demand shocks generate opposite-signed correlations between real exchange rate and current account.

We introduce skill decay during unemployment into a New Keynesian model with hiring frictions and real-wage rigidity. Plausible values of quarterly skill decay and real-wage rigidity turn the long-run marginal cost–unemployment relationship positive in a “European” labor market with little hiring but not in a fluid “American” one. If the marginal cost–unemployment relationship is positive, determinacy requires a passive response to inflation in the central bank's interest feedback rule if the rule features only inflation. Targeting steady-state output or unemployment helps to restore determinacy.

This paper considers an endogenous growth model with public capital and heterogeneous agents. Heterogeneity is due to differences in discount factors and inherent abilities. This allows us to closely approximate the 2007 U.S. income and wealth distributions. Government expenditures, including public investment, are financed through a progressive income tax along with a flat tax on consumption. Three revenue-neutral fiscal policy reforms are considered: (i) an increase in the degree of progressivity of the tax schedule that reduces the after-tax income distribution Gini coefficient to its lowest value over the period 1979–2009, (ii) a reduction in the progressivity ratio that causes the Gini coefficient of the wealth distribution to come close to 1, and (iii) an increase in the fraction of output allocated to public investment that has the same positive impact on the growth rate as reform (ii). It is shown that increasing investment in public capital is the only type of policy that simultaneously enhances growth and reduces both types of inequality (income and wealth). We also find that the public-investment-to-output ratio that maximizes social welfare crucially depends on the elasticity of the labor supply. With a more elastic labor supply the optimal ratio is 4.40%, whereas with a less elastic labor supply it is 5.53%.

I develop a dynamic political economy model with an informal sector and two political parties alternating in office. In equilibrium, if the incumbent political party faces a higher probability of staying in office, it sets a higher tax rate on the formal economy to invest more in productive public capital, while spending less for current office rent. Moreover, I argue that public capital is mainly utilized by the formal sector, and this implies that countries in which incumbent parties are more likely to stay in power have a higher tax burden but a smaller informal sector. I also present some empirical evidence that supports the main results of the model.

Does excluding food and energy prices from the Consumer Price Index (CPI) produce a measure that better captures permanent price changes? To examine this question, we decompose CPI inflation and “core” inflation into their permanent and transitory components, using a correlated unobserved-components model. The stationarity of inflation may be time-varying, so we examine the performance of the core measure of inflation separately for periods in which inflation is I(1) and I(0). For a period in which inflation appears to be I(1), we find that core inflation and the permanent component of overall inflation are closely related, but there are some caveats. For a period in which inflation appears to be I(0), we decompose the core and overall price levels and find that the permanent component of the core CPI is much more volatile than the actual core series and that the core excludes volatile permanent shocks to the overall price level.

In a knowledge-based growth model where skilled workers are used in innovation and production, skill-biased technological change may lower average R&D productivity via an innovation possibilities frontier effect that eliminates scale effects. We show that skill-biased technological change increases the skill premium even if the elasticity of substitution between skilled and unskilled workers is less than two. Trade between developed countries promotes skill-biased technological change, thus raising wage inequality. Trade between developed and developing countries has differing effects: it induces relatively skill-replacing technological change and lowers wage inequality in the developed country but has the opposite effects in the developing country. Finally, we show that trade can stimulate or hurt economic growth.

Now that most countries have harmonized intellectual property right (IPR) legislation as a consequence of signing the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPs), the dispute about the optimal level of IPR protection has shifted toward IPR enforcement. This paper develops an endogenous growth framework with two open economies satisfying the classical North–South assumptions to study (a) the regions' incentives to enforce IPRs in a decentralized game, (b) the desired IPR enforcement of the two regions in negotiation rounds on global harmonization, and (c) the constrained efficient enforcement level. We show how the different solutions relate to each other and how the results depend on the research productivity in the North and the regions' relative market sizes. Although growth rates increase substantially when IPR enforcement is harmonized at the North's desired level, our numerical simulation suggests that the South may also benefit in terms of long-run welfare.

This paper analyzes the dynamics of an endogenous growth model with external habit formation and elastic labor supply. We first derive the conditions for the existence, uniqueness, and saddlepath stability of a feasible steady state with positive long-run growth. The global dynamics of the economy are characterized by phase-diagram analysis. Then we characterize the comparative static effects of shocks in preferences and production parameters analytically. The comparative dynamic effects of the shocks are characterized by phase-diagram analysis.

The main result is that the golden rule equilibrium (GRE) is Pareto optimal (in the classical sense) in an overlapping generations (OG) model with constant-returns-to-scale production, transfers, arbitrary life-time productivity and homogeneous instantaneous felicity. In addition, we extend Cass and Yaari's equivalence between efficiency (aggregate consumption dominance) and present value dominance (with evaluation made using a candidate equilibrium price path).

We develop a growth model where knowledge is embodied in individuals and diffused across sectors through labor mobility. The existence of labor mobility costs constrains mobility and thus generates labor misallocation. Different levels of labor misallocation imply different levels of exploitation of available knowledge and therefore different total factor productivity across countries. We derive a positive relationship between growth and labor mobility, which is consistent with the empirical evidence, by assuming aggregate constant returns to capital. We also analyze the short- and long-run effects of labor mobility costs in the case of decreasing returns to capital. It turns out that changes in mobility costs have larger economic effects when different types of workers have small rather than large complementarities. Finally, we show that different labor income taxes or labor market tightness imply different rates of labor mobility and therefore can explain differences in Gross Domestic Product across countries.

Models of endogenous growth have not been able to account for the variety of empirically observed distributional properties of the returns to innovation, in part, because of the limitations necessarily imposed on competition to cope with increasing returns to scale. Exponential growth, fat tails, Pareto–Levy distributed upper tails, and upper value outliers, are associated with increasing returns to scale and innovation. At the same time, properties such as bifurcated research investment strategies, bimodal returns to innovation, and Laplace distributed firm growth rates are products of competition. We build an agent-based model of endogenous technical change in which heterogeneous investments in patented knowledge and increasing returns to scale emerge these distributional properties within a competitive market. The combination of heterogeneous agents, costly information, and patents allow for a competitive landscape to persist amidst increasing returns. The ability of model to foster a coexistence of competition and increasing returns underlies the observed distributional properties.

This paper studies optimal fiscal policy, in the form of taxation and the allocation of tax revenues between infrastructure and environmental investment, in a general-equilibrium growth model with endogenous subjective discounting. A green spending reform, defined as a reallocation of government expenditures toward the environment, can procure a double dividend by raising growth and improving environmental conditions, although the environment does not impact the production technology. Also, endogenous Ramsey fiscal policy eliminates the possibility of an “environmental and economic poverty trap.” In contrast to the case of exogenous discounting, green spending reforms are the optimal response of the Ramsey government to a rise in the agents' environmental concerns.