NBER Working Papers by Gary Hansen

We study the effects of on-the-job skill accumulation on average hours worked by age and the volatility of hours over the life cycle in a calibrated general equilibrium model. Two forms of skill accumulation are considered: learning by doing and on-the-job training. In our economy with learning by doing, individuals supply more labor early in the life cycle and less as they approach retirement than they do in an economy without this feature. The impact of this feature on the volatility of hours over the life cycle depends on the value of the intertemporal elasticity of labor supply. When individuals accumulate skills by on-the-job training, there are only weak effects on both the steady-state labor supply and its volatility over the life cycle.

We explore the quantitative implications of uncertainty about the length of life and a lack of annuity markets for life cycle consumption in a general equilibrium overlapping generations model in which markets are otherwise complete. Empirical studies find that consumption tends to rise early in life, peak around age 45-55, and to decline after that. Our calibrated model exhibits life cycle consumption that is consistent with this pattern. This follows from the fact that, due to a lack of annuity markets, households discount the future more heavily as they age and their probability of survival falls. Once an unfunded social security system is introduced, the profile is still hump shaped, but the decline in consumption does not begin until after retirement in our base case. Adding a bequest...

This paper shows that a standard Real Business Cycle model driven by productivity shocks can successfully account for the 50 percent decline in cyclical volatility of output and its components, and labor input that has occurred since 1983. The model is successful because the volatility of productivity shocks has also declined significantly over the same time period. We then investigate whether the decline in the volatility of the Solow Residual is due to changes in the volatility of some other shock operating through a channel that is absent in the standard model. We therefore develop a model with variable capacity and labor utilization. We investigate whether government spending shocks, shocks that affect the household's first order condition for labor, and shocks that affect the househol...

A unified growth theory is developed that accounts for the roughly constant living standards displayed by world economies prior to 1800 as well as the growing living standards exhibited by modern industrial economies. Our theory also explains the industrial revolution, which is the transition from an era when per capita incomes are stagnant to one with sustained growth. This transition is inevitable given positive rates of total factor productivity growth. We use a standard growth model with one good and two available technologies. The first, denoted the capital as inputs. The second, denoted the does not require land. We show that in the early stages of development, only the Malthus technology is used and, due to population growth, living standards are stagnant despite technological ...