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].

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.

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 builds on Lucas [Econometrica 68 (2000), 247–274] and on Cysne [Journal of Money, Credit and Banking 35 (2003), 221–238] to derive and order six alternative measures of the welfare costs of inflation (five of them already existing in the literature) for any vector of opportunity costs. We provide examples and closed-form solutions for each welfare measure based both on log–log and on semilog money demands, whenever possible in terms of elementary functions. Estimates of the maximum relative error a researcher can incur when using any of these measures are given. Everything is done for economies with or without interest-bearing deposits.

We develop business-cycle models with financial constraints, the driving force of which is news about the future (i.e., changes in expectations). We assume that an asset with fixed supply (“land”) is used as collateral, and firms need to hold collateral to finance their input costs. The latter feature introduces an interaction between the inefficiencies in the financial market and in the factor market. Good news raises the price of land today, which relaxes the collateral constraint. It, in turn, reduces the inefficiency in the labor market. If this force is sufficiently strong, the equilibrium labor supply increases. So do output, investment, and consumption. Our models also generate procyclical movement in Tobin's Q. We also show that when the news turns out to be wrong, the economy may fall into a recession.

Using a macroeconomic model with asset prices, we analyze how optimal monetary policy and macroeconomic dynamics and performance are affected by a central bank's desire to be robust against model misspecifications. We show that a higher central bank preference for robustness implies a more aggressive reaction of the nominal interest rate to the expected future inflation rate and inflation shocks. The dynamic stability of the equilibrium is not modified for a sufficiently high preference for robustness. However, the speed of dynamic convergence is lower under robust control compared to a benchmark case without it and implies supplementary economic costs. Finally, an increase in the preference for robustness comes at the cost of higher macroeconomic and financial volatility in the presence of inflation shocks. It has no effect on the reaction of inflation, output gap, and asset price gap to shocks affecting goods and financial markets.

When the production function includes dynamic complementarities and a Cobb--Douglas form, dynamic complementarities are an endogenous propagation mechanism of shocks. The proposed model explains several stylized facts of aggregate variables of interest, including (i) hump-shaped impulse response functions, (ii) positively autocorrelated growth rates of aggregate variables, and (iii) correlation coefficients of forecastable movements in aggregate variables.

This note uses a nonlinear structural vector autoregression model to empirically investigate the effectiveness of official foreign exchange (FX) interventions in an economy when interest rates are constrained to the zero level, based on Japanese data in the 1990s. The model allows us to estimate the effects of FX interventions operating through different channels. We find that FX interventions are still capable of influencing the foreign exchange rate in a zero-interest-rate environment, even though their effects are greatly reduced by the zero lower bound on interest rates. Our results suggest that although it might be feasible to use the exchange rate as an alternative monetary policy instrument at zero interest rates as proposed by McCallum (Inflation Targeting and the Liquidity Trap, NBER working paper 8225, 2000), the exchange rate–based Taylor rule may not be very effective in achieving the ultimate policy goals.