The dynamics of macroeconomic and financial series has evolved swiftly and asymmetrically since the end of the 1970s, and their statistical properties have also changed over time, suggesting complex relationships between economic and financial variables. The transformations can be explained by considerable changes in householder's behavior, market structures, and economic systems and by the alternation of exogenous shocks and financial crises that have affected the economic cycle, with significant evidence of time variation in the major economic variables. Hence, there is a need for new econometric protocols to take such changes into consideration. The introduction of ARMA (autoregressive moving average models) by Box and Jenkins (1970) led to the development of time-series econometrics, which had a major impact on the conceptual analysis of economic and financial data. This type of modeling offered a transition from a static setup to a new modeling process that reproduces the time-varying features of macroeconomic and financial series. However, the ARMA modeling system retains the constancy of the first and second moments, limits the phases of a cycle to symmetrical instances, and only reproduces the dynamics of stationary variables. It thus fails to adequately reproduce the nonstationary relationships between major economic and financial variables. Abrupt changes in economies and financial systems have given evidence of nonstationary series whose statistical properties are also time-varying, making it necessary to develop new econometric tools to capture the time variation of economic and financial series in the mean and in the variance, and to apprehend their dynamics in the short and long term. Among the most important and influential studies in the 1980s' econometrics literature were therefore those that dealt with the introduction of the ARCH (autoregressive conditional heteroskedasticity) model by Engle (1982) and the cointegration theory by Engle and Granger (1987). The ARCH model, which focuses on the time-varying features of volatility structure, was a major breakthrough, as it highlighted the importance of the second moment of time series, while the cointegration framework enabled the short- and long-term dynamics of nonstationary variables to be modeled.

We introduce a model of the optimal education policy at the macro level, allowing for heterogeneity of the workforce with respect to its age and qualification skills. Within this framework we study the optimal education rate in the context of changes in labor demand (as represented by the elasticity of substitution across ages and qualification) and labor supply (as represented by a change in the population growth rates). Applying an age-structured optimal-control model, we derive features of the optimal age-specific education rate. Our results show that the relation between the elasticities of substitution of labor across ages plays a crucial role in the way the demographic changes affect (both in the short and in the long run) the optimal educational policy. We also show that under imperfect substitutability across age and qualification groups, the optimal educational policy is adjusted in advance to any change in the labor supply.

This paper attempts to determine the factors generating the persistence of unemployment over the business cycle. The observations show that the total unemployment rate is highly persistent, and that the persistence of the unemployment rate of unskilled workers is higher than that of skilled workers. To account for these observations, the paper develops a framework that features search frictions. Individuals are either high educated or low educated, and firms post two types of vacancies: the complex, which can be matched with the high educated, and the simple, which can be matched with the high and the low educated. On-the-job search for a complex occupation is undertaken by the high educated in simple occupations. A negative aggregate technological shock induces the high educated unemployed to compete with the low educated by increasing their search intensity for simple vacancies. As the high educated occupy simple vacancies, they crowd out the low educated into unemployment. This downgrading of jobs in a cyclical downturn, or the increase in the labor input of the high educated in simple occupations, and the subsequent crowding out of the low educated into unemployment, provide a possible explanation for unemployment persistence.

Over the past three decades, analysis of dynamics has come to the forefront of macroeconomic theory. A key impetus for progress on this front has been the connections developed between equilibrium growth theory, on one hand, and the field of nonlinear dynamics, on the other. Kazuo Nishimura's work has been at the center of these advances, and the lines of research he initiated remain an exciting area of study for young researchers with strong technical skills.

When finite lifetime is introduced in a Lucas [Journal of Monetary Economics 22 (1988), 3–42] growth model where the source of pollution is physical capital, the environmental policy may enhance the growth rate of a market economy, whereas pollution does not influence educational activities, labor supply is not elastic, and human capital does not enter the utility function. The result arises from the generational turnover effect due to finite lifetime and it remains valid under conditions when the education sector uses final output as well as time to accumulate human capital. This article also demonstrates that ageing reduces the positive influence of environmental policy when growth is driven by human capital accumulation à la Lucas in the overlapping-generations model of Yaari [Review of Economic Studies 32 (1965), 137–150] and Blanchard [Journal of Political Economy 93 (1985), 223–247].

Galor and Ryder [Journal of Economic Theory 49 (1989), 360–375] establish conditions for the existence of equilibrium in a Diamond-type overlapping-generations (OLG) model. Although theoretically appealing, these conditions are implicit and not convenient to apply. This paper provides explicit and easily applied conditions for the existence and uniqueness of steady-state equilibrium, with which one only needs to check the first derivatives of the production and utility functions and their interactions, with no need to solve the optimization problem. Our theorems on the existence and uniqueness of steady-state equilibrium can be applied to a larger class of OLG models that do not require second-order differentiability of the production and utility functions. We present examples to show how to check the existence and uniqueness of equilibrium.

This paper constructs a quantitative general equilibrium life-cycle model with uninsurable labor income to account for the differences in wealth accumulation and homeownership between Korea and the United States. The model incorporates different structures in the housing market in the two countries, namely, the mortgage market and the rental arrangements. The results from the calibrated model quantitatively explain some empirical findings in the aggregate and life-cycle profiles of wealth and homeownership. Quantitative policy experiments show that the mortgage market alone can account for more than 40% of the differences in the aggregate homeownership ratios. When coupled with the rental arrangements, both institutions can account for approximately 52% of the differences in the cross-country homeownership ratios.

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.

We discuss the problem known in economics as backward dynamics occurring in models of perfect foresight, intertemporal equilibrium described mathematically by implicit difference equations. In a previously published paper [Journal of Economic Dynamics and Control 31 (2007), 1633–1671], we showed that by means of certain mathematical methods and results known as inverse limits theory it is possible to establish a correspondence between the backward dynamics of a noninvertible map and the forward dynamics of a related invertible map acting on an appropriately defined space of sequences, each of whose elements corresponds to an intertemporal equilibrium. We also proved the existence of different types of topological attractors for one-dimensional models of overlapping generations. In this paper, we provide an extension of those results, constructing a Lebesgue-like probability measure on spaces of infinite sequences that allows us to distinguish typical from exceptional dynamical behaviors in a measure–theoretical sense, thus proving that all the topological attractors considered in MR07 are also metric attractors. We incidentally also prove that the existence of chaos (in the Devaney–Touhey sense) backward in time implies (and is implied by) chaos forward in time.

In this paper I show that the intensity at which intermediate goods are used in the production process affects aggregate total factor productivity (TFP). To do this, I construct an input–output model economy in which firms produce gross output by means of a production function in capital, labor, and intermediate goods. This production function is subject, together with the standard neutral technical change, to intermediates-biased technical change. Positive (negative) intermediates-biased technical change implies a decline (increase) in the elasticity of gross output with respect to intermediate goods. In equilibrium, this elasticity appears as an explicit part of TFP in the value added aggregate production function. In particular, when the elasticity of gross output with respect to intermediates increases, aggregate TFP declines. I use the model to quantify the impact of intermediates-biased technical change for measured TFP growth in Italy. The exercise shows that intermediates-biased technical change can account for the productivity slowdown observed in Italy from 1994 to 2004.

In this paper I build a unified model of economic growth to account for the time-series evolution of output, fertility, and population in the industrialization of an economy. Specifically, I merge the unified growth models of Galor and Weil [American Economic Review 90 (2000), 806–828] and Hansen and Prescott [American Economic Review 92 (2002), 1205–1217] to capture the importance of human capital formation, fertility decline, and the transition from agriculture to industry in transition from stagnation to growth. Moreover, I also incorporate young adult mortality into the model. Initially, the aggregate human capital and return to education are low and the mortality rate is high; therefore parents invest in quantity of children. Once sufficient human capital is accumulated and mortality rates are reduced, thanks to increasing life expectancy, with the activation of the modern human capital–intensive sector, parents start to invest in the quality of their children. The simulation of the model economy improves upon the quantitative performance of the existing literature and successfully captures the evolution of fertility, population, and GDP in the British economy between 1750 and 2000.

In this paper we study the role of bank capital adequacy requirements in the transmission of aggregate productivity shocks. We identify a gap between the empirical and the theoretical work that studies the “credit crunch” effects of these requirements, and how they can work as a financial accelerator that amplifies business cycles. This gap arises because the empirical work faces some difficulties in identifying the effects of capital requirements, whereas the theory still lacks a structural framework that can address these difficulties. We bridge that gap by providing a general equilibrium theoretical framework that allows us to study this financial accelerator. The main insight we obtain is that the “credit crunch” and financial accelerator effects are rather weak, which confirms the findings of existing empirical work. Additionally, by developing a structural framework, we are able to provide an explanation for this result.

We incorporate keeping-up-with-the-Joneses (KUJ) preferences into the Blanchard–Yaari framework and develop a model of balanced growth. In this context we investigate status preference, demographic shocks, and pension policy. We find that a higher degree of KUJ lowers economic growth, whereas, in contrast, a decrease in the fertility and mortality rates increase it. In the second part of the paper we extend the model by incorporating a pay-as-you-go (PAYG) pension system with a statutory retirement date. The latter implies that the growth rate is higher under PAYG. We also consider the implications of pension reform under both defined benefit and defined contribution schemes.

Theoretically, two-country real business cycle models with time-separable preferences and complete markets predict that cross-country investment correlations will be negative. The opposite is true in the data. This phenomenon has been described by Backus et al. [in Cooley (ed.), Frontiers of Business Cycle Research, pp. 331–356 (Princeton, NJ: Princeton University Press, 1995)] as a quantity anomaly. This paper proposes to address this discrepancy by allowing the nonseparability of preferences over time. Here, we incorporate internal habit formation into consumption. Our model predicts the empirically plausible value of cross-country investment correlation without sacrificing other business cycle statistics. The results are robust to the degree of spillovers and persistence in the specification of the productivity shocks.

We analyze the role of the lending-deposit interest rate spread in the dynamics of the current account in developing countries. For that purpose, we extend the standard perfect-foresight intertemporal model of the current account for the existence of the interest rate spread and simulate the convergence path of developing economies. This model helps explain why in many cases it is optimal for a fast-growing, low-income country to run a balanced current account.

It is a great honor and a great pleasure for me to pay tribute to the accomplishments of Kazuo Nishimura on the occasion of this special issue. He is a great scientist, whose contributions I deeply admire and respect, and he is a good friend.

For two independent principles of intergenerational equity, the implied discount rate equals the growth rate of real per capita income, say, 2%, thus falling right into the range suggested by the U.S. Office of Management and Budget. To prove this, we develop a simple tool to evaluate small policy changes affecting several generations, by reducing the dynamic problem to a static one. A necessary condition is time invariance, which is satisfied by any common solution concept in an overlapping-generations model with exogenous growth. This tool is applied to derive the discount rate for cost–benefit analysis under two different utilitarian welfare functions: classical and relative. It is only with relative utilitarianism, and assuming time-invariance of the set of alternatives (policies), that the discount rate is well defined for a heterogeneous society at a balanced growth equilibrium, is corroborated by an independent principle equating values of human lives, and equals the growth rate of real per-capita income.

Inspired by the theoretically oriented dynamic analysis of moving average rules in the model of Chiarella, He, and Hommes (CHH) [Journal of Economic Dynamics and Control 30 (2006), 1729—1753], this paper conducts a dynamic analysis of a more realistic microstructure model of continuous double auctions in which the probability of heterogeneous agents trading is determined by the rules of either fundamentalists mean-reverting to the fundamental or chartists choosing moving average rules based on their relative performance. With such a realistic market microstructure, the model is able not only to obtain the results of the CHH model but also to characterize most of the stylized facts including volatility clustering, insignificant autocorrelations (ACs) of returns, and significant slowly decaying ACs of the absolute returns. The results seem to suggest that a comprehensive explanation of several statistical properties of returns is possible in a framework where both behavioral traits and realistic microstructure have a role.

The fraction of the labor force under 35, or youth share, has been correlated with cyclical GDP volatility over the past several decades. The youth share and business cycle fluctuations were high during the 1970s. Then, as the population aged, output volatility declined. I develop an overlapping generations model featuring search frictions and productivity shocks, in which the age distribution affects cyclical volatility through two channels. First, employment for younger workers fluctuates more, creating a composition effect. Second, inexperienced workers produce less, so firms decide how many jobs to create based on the age distribution. Both this endogenous response by firms and the composition effect increase aggregate volatility when the youth share is high. The model can replicate a large portion of the Great Moderation in GDP volatility, suggesting an important role for demographics. The model also replicates unemployment rates, separation rates, and employment volatility by age group.

This paper provides evidence on monetary policy transmission for five key emerging market economies: Brazil, Russia, India, China, and South Africa. Monetary policy (interest rate) shocks are identified using modern Bayesian methods along with the more recent sign restrictions approach. We find that contractionary monetary policy has a strong and negative effect on output. We also show that such contractionary monetary policy shocks do tend to stabilize inflation in these countries in the short term, while producing a strongly persistent negative effect on real equity prices. Overall, the impulse responses are robust to the alternative identification procedures.