Research Database

This paper formalizes and quantifies the secular stagnation hypothesis, defined as a persistently low or negative natural rate of interest leading to a chronically binding zero lower bound (ZLB). Output-inflation dynamics and policy prescriptions are fundamentally different from those in the standard New Keynesian framework. Using a 56-period quantitative life cycle model, a standard calibration to US data delivers a natural rate ranging from -1.5% to -2%, implying an elevated risk of ZLB episodes for the foreseeable future. We decompose the contribution of demographic and technological factors to the decline in interest rates since 1970 and quantify changes required to restore higher rates.

The existence of fixed points for monotone maps on spaces of measures is established. The case of monotone Markov processes is analyzed and a uniqueness and global stability condition is developed. A comparative statics result is presented and the problem of approximation to the invariant distribution is discussed. The conditions of the theorems are verified for the cases of Optimal Stochastic Growth and Industry Equilibrium.

We describe a model for calculating the optimal quantity of debt and then apply it to the U.S. economy. The model consists of a large number of infinitely-lived households whose saving behavior is influenced by precautionary saving motives and borrowing constraints. This model incorporates a different role for government debt than the standard representative agent growth model and captures different trade-offs between the benefits and costs of varying its level. Government debt enhances the liquidity of households by providing additional assets for smoothing consumption (in addition to claims to capital) and effectively loosening borrowing constraints. By raising the interest rate, government debt makes assets less costly to hold and more effective in smoothing consumption. However, the implied taxes have wealth distribution, incentive, and insurance effects. Further, government debt crowds out capital (via higher interest rates) and lowers per capita consumption. Our quantitative analysis suggests that the crowding out effect is decisive for welfare. We also describe variations of the model which permit endogenous growth. It turns out that even with lump sum taxes and inelastic labor, government debt as well as government consumption have growth rate effects, thereby implying large welfare gains from reducing the level of debt.

This note presents a model whose competitive equilibrium can be consistent with the observation that current labor market conditions affect the well-being of new entrants more than they do that of senior workers. The model uses the notion that new entrants are not around soon enough to participate in risk-sharing contingent on the shocks that determine the equilibrium marginal products of first-period employment. This timing notion is formalized using a stochastic overlapping generations model.

A problem facing the United States and many other countries is how to finance retirement consumption as the number of their workers per retiree falls. The problem with a savings for retirement systems is that there is a shortage of good savings opportunities given the nature of most current tax systems and governments’ limited ability to honor the debt it issues. We find that eliminating capital income taxes will greatly increase saving opportunities and make a savings-for-retirement system feasible with only modest amount of government debt. The switch from a system close to the current U.S. retirement system, which relies heavily on taxing workers’ incomes and making lump-sum transfers to retirees, to one without income taxes will increase the welfare of all birth-year cohorts alive today and particularly the welfare of the yet unborn cohorts. The equilibrium paths for the current and alternative policies are computed.

We examine an otherwise standard model of capital accumulation to which spatial separation and limited communication create a role for money and shocks to portfolio needs create a role for banks. In this context we examine the existence, multiplicity, and dynamical properties of monetary equilibria with positive nominal interest rates. Moderate levels of risk aversion can lead to the existence of multiple monetary steady states, all of which can be approached from a given set of initial conditions. In addition, even if there is a unique monetary steady state, monetary equilibria can be indeterminate, and oscillatory equilibrium paths can be observed. Thus financial market frictions are a potential source of both indeterminacies and endogenously arising economic volatility.

We also consider the consequences of monetary policy actions that rearrange the composition of government liabilities. Contractionary monetary policy activities can have complicated consequences, depending especially on the nature of the steady state equilibrium that obtains when there are multiple steady states. Under plausible conditions, however, a permanent contractionary change in monetary policy raises both the nominal rate of interest and the rate of inflation, and reduces long-run output levels. Thus liquidity provision by a central bank—just as by the banking system as a whole—can be growth promoting. Loose monetary policy also is conducive to avoiding development trap phenomena.