In this article we use Bayesian classification and finite mixture models to extract information from the MSI database (maintained by the Federal Reserve Bank of St. Louis) and construct a new set of non-nested monetary aggregates (under the Divisia aggregation procedure) based on statistical similarities and multidimensional structures. We also use recent advances in the fields of applied econometrics, dynamical systems theory, and statistical physics to investigate the relationship between the new money measures and economic activity. The empirical results offer practical evidence in favor of this approach to monetary aggregation.

This paper investigates the link between consumer pessimism and U.S. economic recessions empirically. First we use structural vector autoregressive models to identify negative structural shocks to consumer confidence, which are used as a proxy for recession fear. We then apply probit models and time-varying-transition-probability Markov-switching autoregressive models to investigate how the lack of consumer confidence affects the probability of recession. We find that recession fear leads to a higher probability of economic downturns. Furthermore, strong evidence exists that an increase in market pessimism may push the economy from an expansion state to a recession state. We also find weaker evidence suggesting that a lack of consumer confidence may trap the economy in the depressed regime longer. We conclude that a lack of confidence can push the economy into recession.

This paper proposes a Bayesian approach to estimating a factor-augmented GDP per capita equation. We exploit the panel dimension of our data and distinguish between individual-specific and time-specific factors. On the basis of 21 technology, infrastructure, and institutional indicators from 82 countries over a 19-year period (1990 to 2008), we construct summary indicators of each of these three components in the cross-sectional dimension and an overall indicator of all 21 indicators in the time-series dimension and estimate their effects on growth and international differences in GDP per capita. For most countries, more than 50% of GDP per capita is explained by the four common factors we have introduced. Infrastructure is the greatest contributor to total factor productivity, followed by technology and institutions.

Carbon pricing aims to shift the risk-adjusted returns on investment in favor of green technologies vis-‘a-vis fossil investment, relying on efficient capital markets to redirect investment accordingly. Capital markets with financial frictions can distort this transmission of climate policy. This study analyses the impact of emission taxes on mitigation and low-carbon investment in the presence of financial frictions. We develop a two-sector environmental dynamic stochastic general equilibrium model calibrated to the Euro Area, to simulate an economic transition in line with the EU climate targets. Financial frictions dampen the response of the economy to the carbon tax such that the emissions target will be missed by 11 percentage points. Moreover, the adverse effects of financial frictions increase when climate policy is delayed. We further identify a volume and a risk effect that drive the impact of a financial wealth shock and an uncertainty shock on emission intensity.

This article presents a Ricardian model of trade with learning-by-doing to study the effect of barriers to trade in products with low growth potential on the long-run economic growth. The model shows that, when elasticity of demand for the product with a lower learning potential is greater than unity, a tariff imposed on this product can shift the demand toward the product with a higher learning potential, thus enhancing growth in the exporter economy. Therefore, although with some possible negative effect on the welfare in the short run, barriers for the export of natural luxury goods may be beneficial for developing economies in the long run, since they increase their incentive to develop sectors with higher growth potential.

By concentrating a stimulus on the domestic economy, Buy National clauses are argued to lead to higher fiscal multipliers. We show that this argument falls short. Although it is true that domestic demand for domestic goods is increased, at the same time foreign demand for domestic goods is reduced by adverse changes in the real exchange rate. The two effects are of similar magnitude, so that Buy National clauses do not lead to a stronger stimulus to GDP. Apart from that, restricting the stimulus to domestic products makes the stimulus more expensive, because cheap foreign products are ignored. Consequently, real public consumption is lowered by Buy National clauses.

This paper revisits two classic results in standard overlapping generations models with a pay-as-you-go (PAYG) pension system. Firstly, a PAYG system crowds out private savings and reduces the overall capital stock. Secondly, in dynamically efficient economies, a PAYG system will reduce steady-state welfare. These classic results have been derived and exposed in models with no retirement decision. However, by allowing for endogenous retirement, and without taking recourse to any frictions, uncertainty, or myopia, it is shown that a PAYG system may be neutral and may even increase the capital–labor ratio. In particular, it is shown that the effect of the pension contribution rate on capital intensity depends on the elasticity of substitution between consumption and leisure. If the elasticity of substitution is between 0 and 1, an increase in the contribution rate will increase capital intensity. Moreover, it is shown that the result regarding welfare may also be overturned. An increase in the PAYG contribution rate may increase steady-state welfare.

This paper compares different implementations of monetary policy in a new-Keynesian setting. We can show that a shift from Ramsey optimal policy under short-term commitment (based on a negative feedback mechanism) to a Taylor rule (based on a positive feedback mechanism) corresponds to a Hopf bifurcation with opposite policy advice and a change of the dynamic properties. This bifurcation occurs because of the ad hoc assumption that interest rate is a forward-looking variable when policy targets (inflation and output gap) are forward-looking variables in the new-Keynesian theory.

Many studies have stressed that human activities may cause the extinction of single species. Anthropogenic activities, however, may affect not only the number of individuals of single species, but also their behavior. To investigate this issue, we propose a growth model in which agents may care not only for the species’ survival but also for the typicality of their behavior. We assume that the environmental defensive expenditures can protect the species avoiding their extinction, but can induce the species to modify their behavior. Results emerging from the model suggest that if the social planner cares for typicality of species behavior, then an infinite growth process may no longer be optimal. Numerical simulations, moreover, show the possible existence of a trade-off between number and behavior of the species, leading the system to a high number of species’ members that behave in an atypical way or to few members behaving very typically.

Axel Leijonhufvud made an enormous impact on macroeconomics in the late 1960s with the publication of his book On Keynesian Economics and the Economics of Keynes: A Study of Monetary Economics (1968). In this famous book, Leijonhufvud argued that the standard neoclassical synthesis (Hicks–Hansen IS-LM) interpretation of the General Theory totally misunderstood and misinterpreted Keynes. However, during the 1970's, interest in Keynes and Keynesian models waned as new classical equilibrium models became all the rage. Nevertheless, Leijonhufvud, from a position outside the mainstream, continued his research into problems of unemployment, business cycles, and inflation—issues that from his perspective are problems of coordination failure in complex dynamical systems. Axel Leijonhufvud is currently Professor Emeritus at the University of California, Los Angeles, and, since 1995, Professor of Monetary Economics at the University of Trento, Italy. In this interview the author discusses with Leijonhufvud a wide range of issues relating to his own work as well as his views on the development of macroeconomics after Keynes.

This paper revisits the long-run relationship between inflation and economic growth by exploring the impact of inflation on investment. I illustrate that inflation may have a positive effect on growth by mitigating the liquidity risks of investment projects. Together with the traditional effect of the “inflation tax” on investment, a hump-shaped relationship between inflation and economic growth can be obtained in a calibrated model, which is consistent with the US postwar data. Sensitivity analysis suggests that the degree of financial development and the magnitude of the aggregate liquidity demand help explain the mixed empirical findings.

We build a stochastic discount factor—SDF—using U.S. domestic financial data only, and provide evidence that it accounts for stylized facts about foreign markets that escape SDFs generated by consumption-based models. When our SDF is interpreted as the projection of the pricing kernel from a fully specified model in the space of returns, our results indicate that a model that accounts for the behavior of domestic assets goes a long way toward accounting for the behavior of foreign asset prices. In our tests, we address predictability, a defining feature of the forward premium puzzle—FPP—by using instruments that are known to forecast excess returns in the moment restrictions associated with Euler equations both in the equity and in the foreign markets.

We build quadratic labor adjustment costs into an otherwise standard New Keynesian model of the business cycle and show that this increases output persistence in a vein similar to that of other models of labor market frictions. Furthermore, we demonstrate the implication of quadratic labor adjustment costs for monetary policy. We show that there is a simple rule determining whether quadratic labor adjustment costs imply a trade-off between stabilizing inflation and output.

In a second-best optimal growth setup with only factor taxes, it is in general optimal to fully replace capital by labor income taxation in the long run. We revisit this important issue by developing a human-capital-based endogenous growth model with frictional labor search, allowing each firm to create multiple vacancies and each worker to determine market participation. We find that the conventional efficient bargaining condition is necessary but not sufficient for achieving constrained social optimality. We then conduct tax incidence exercises in balanced growth by calibrating to the U.S. economy with a preexisting 20% flat tax on capital and labor income. Our quantitative results suggest that, due to a dominant channel via the interactions between vacancy creation and market participation, it is optimal to switch only partially from capital to labor taxation in a benchmark economy where human-capital formation depends on both physical and human-capital stocks. This main finding is robust even along the transition with time-varying factor tax rates. Moreover, our quantitative analysis under alternative setups suggests that while endogenous human capital and labor-market frictions are essential for obtaining a positive optimal capital tax, endogenous leisure, nonlinear human-capital accumulation and endogenous growth are not crucial.

A simple asset pricing model with both endogenous stock market participation and subjective risk can explain the negative cross-country correlation between participation rates and the volatility of excess returns, along with the time-varying participation rates in the data. Belief-driven learning dynamics can explain the interplay between participation rates, subjective risk, and stock price volatility. When agents adaptively learn about the risk and return, my model generates 25% of the excess volatility observed in US stock prices, while also matching key moments. With learning about risk, excess volatility of stock prices is driven by fluctuations in the participation rate that arise because agents’ risk estimates vary with prices. I find that learning about risk is quantitatively more important than learning about returns.

In the economics literature, there are two dominant approaches for solving models with optimal experimentation (also called active learning). The first approach is based on the value function and the second on an approximation method. In principle the value function approach is the preferred method. However, it suffers from the curse of dimensionality and is only applicable to small problems with a limited number of policy variables. The approximation method allows for a computationally larger class of models, but may produce results that deviate from the optimal solution. Our simulations indicate that when the effects of learning are limited, the differences may be small. However, when there is sufficient scope for learning, the value function solution seems more aggressive in the use of the policy variable.

This paper extends the existing theories of directed technical change by allowing the factors of production, skilled, and unskilled workers, to be employed in both the skill-intensive and unskilled-intensive sectors. Consequently, the direction of technical progress and the sectoral allocation of factors are jointly determined. The feedback between technical progress and the allocation of factors leads to new results concerning structural change and directed technical change. An increase in the endowment of a factor leads to a dynamic reallocation of factors toward the sector that uses the factor intensively. The reallocation of factors also affects the stability properties of directed technical change. When the parameter conditions necessary for strong bias are satisfied, the interior regime (nonspecialization) is at most locally stable. More importantly, if the relative endowment of skilled labor becomes too high (low), the economy necessarily specializes in the production of skilled (unskilled)-labor-intensive goods. Last, the relationship between the relative endowment of skilled labor and the steady-state relative wage rate is not necessarily monotonic.

This paper focuses on the question of what monetary and fiscal policy can do and should do in a “fiscal dominance” world. I first highlight that both “amplification” and “fiscal cushion” effects are always at work jointly in determining the evolution of inflation. I find the threshold of maturity of government bonds beyond which more aggressive monetary policy dampens inflation volatility is three quarters. In addition, I conduct welfare analysis to quantitatively evaluate the costs and benefits brought by long-term debt. My results show that the threshold of government debt maturity above which an aggressive monetary policy improves welfare is eight quarters. More importantly, I characterize optimal monetary and fiscal policy using simple and implementable rules. My results indicate an optimal monetary and fiscal combination calls for an aggressive response in both rules. Finally, I find that optimized simple monetary-fiscal rule is significantly welfare inferior to the Ramsey optimal policy.

We obtain the transitional dynamics of the decentralized economy described by P.M. Romer and characterize the dynamic behavior of the most relevant variables. We determine the existence of a stable one-dimensional manifold containing a steady state with innovation, unique in ratios, and also find a threshold in the accumulation of physical capital below which the economy is not innovating. Finally, using simulations, we assess the significance of this threshold and analyze the influence that technological and utility parameters have on it.

In previous papers [Spear and Young (2014, 2015)], we surveyed the origins, evolution, and dissemination of optimal growth, two-sector and turnpike models up to the early 1970s. Regarding subsequent developments in growth theory, a number of prominent observers, such as Fischer (1988), Stern (1991), and McCallum (1996), maintained that after significant progress in the 1950s and 1960s, economic growth theory “received relatively little attention for almost two decades” [Fischer (1988, p. 329)], and that “by the late 1960s early 1970s, research on the theory of growth more or less stopped” [Stern (1991, p. 259)]. Stern went on to say “the latter half of the 1980s saw a rekindling of growth theory, particularly in the work of Romer . . . and Lucas” (1991, p. 259), that is to say, in the form of “endogenous growth” models. McCallum, for his part, wrote (1996, p. 41), “After a long period of quiescence, growth economics has in the last decade (1986–1995) become an extremely active area of research.” Moreover, Brock and Mirman's (1972b) paper was the sole “extension” of Ramsey–Cass–Koopmans to a “stochastic environment” mentioned by McCallum (1996, 49).