New Releases by Laurence J. KOTLIKOFF

This paper examines the efficiency gains from linking marginal Social Security benefits to marginal Social Security payroll taxes. In the U.S. the current combined employer-employee OASI payroll tax rate is 10.4 percent. Recent estimates suggest that the average marginal income tax rate is roughly 27 percent (Barro and Sahaskul (1983)). If marginal OASI payroll taxes provided no marginal Social Security benefits or were incorrectly perceived to provide nomarginal benefits, the effective marginal federal government taxation of labor supply would average roughly 38 percent. Since the efficiency costs of distortionary taxation rise as roughly the square of the tax rate, the Social Security payroll tax may be more than doubling the dead weight loss of labor income taxation.The findings of this paper suggest that there may be very significant efficiency gains available from tightening the connection between marginal Social Security taxes paid and marginal Social Security benefits received. Indeed, the simulated efficiency gains are very large in comparison with those obtained from analyses of the gains from structural tax reform. Restructuring Social Security to greatly enhance marginal benefit-tax linkage may be infeasible, at least in the short run. However, simply providing annual Social Security reports indicating how a worker''s projected benefits are affected by his or her tax contributions could provide substantial increases in economic efficiency. Such efficiency gains are potentially as large as increasing GNP by 1 percent this year and every year in the future

The U.S. and other western economies are experiencing dramatic changes in growth and age structure of their populations. Fluctuations in birth rates are the most important determinants of these changes in the post war period. This paper examines the dynamic effects of baby "booms" and baby"busts" on a range of economic variables using a perfect foresight life cycle simulation model. In addition to describing general transition (as opposed to simply long run) affects of fertility change, the paper considers alter-native Social Security policies for avoiding sharp increases in long run payroll tax rates. These include reductions in benefit replacement rates, advances in Social Security''s retirement age, taxation of social security benefits, and the accumulation of a significant Social Security trust fund. According to the simulated demographic transitions, the savings inthe U.S. fertility currently underway can have very major impacts on long run factor returns and produce percipitous short term changes in saving rates. While Social Security policy has important effects on the simulated demographic transitions, these effects are of secondary importance to the long run level of economic welfare. Even if payroll tax rates rise dramatically, long run welfare (measured in terms of levels of adult consumption and leisure) is, nonetheless, substantially higher in the case of a sustained dropin the fertility rate. This reflects, in part, the decline in the number of dependent children per adult; while a sustained decline in the fertility rate eventually means a much larger ratio of elderly per capita, the decline in children per capita means an overall decline in the long run ratio of dependents to prime age workers in the economy. A second explanation for the simulated long run welfare gains is capital deepening associated with lower population growth rates

Distingiishing "spot" versus "contract" views of the labor market is of critical importance to a host of economic issues ranging from wage flexibility over the business cycle to firm financial valuation. The structural features of U.S. private pension plans permit surprisingly strong inferences concerning the incentive effects of private pension plan provisions and the contractual nature of the U.S. labor market. This paper examines the accrual of vested pension benefits of a nation-wide sample of pension plans. We find strikingly larged is continuities in the profile by age of the ratio of annual accrued pension benefits to the standard wage. These discontinuities primarily occur at the ages of full vesting and early retirement. Representative plans often exhibit absolute changes in accrual ratios of 20 to 30 percentage points at these ages.The provisions of many plans imply large negative accruals after the age of early retirement. Job change typically involves a large loss in pension wealth as well. Since the average worker''s marginal product presumably changes smoothly as he or she ages, these pension data can only be reconciled with spotmarket clearing if age wage profiles within a firm exhibit exactly offsetting discontinuities at key ages. Casual inspection of firm wage setting behavior rules out this requirement of spot market clearing. In our view the magnitude,patterns, and variations in pension accrual ratios are strikingly at odds with spot market equilibrium. While market clearing in longer term contracts seems the only equilibrium theory consistent with these findings, it also strains our credulity to ascribe optimizing behavior to the pension accrual profiles chosen by a vast array of U.S. businesses. In the process of presenting these profiles we also consider the following questions concerning U.S. pensions. What are the incentive effects of private pension plans? What is the cost in pension benefits of job turnover? How important is vesting? Is there a cost in pension benefits of foregoing the early retirement option? Do pension stipulations encourage early retirement? While the considerable heterogeneity of pension plan provisions permits no simple or single answer to these questions, the data suggest that pensions can have major incentive effects on job turnover and retirement. In general pensions represent a very significant factor, and at certain ages, a dominant factor in employee compensation.

In neoclassical models of consumption choice under earnings uncertainty changes in consumption programs from one period to the next are determined by new information received about future earnings over the period. This proposition suggests testing the neoclassical model by ascertaining whether new earnings information explains consumption choice through time. It also suggests that actual consumption choices imbed extractable information about the extent and time resolution of earnings uncertainty. This paper derives a fairly general theoretical relationship between properly defined innnovations in consumption (noise) and revisions in expectations of lifetime earnings (news). It also clarifies the relationship between testing for the theoretical determinants of consumption and standard Euler tests that focus on theoretical nondeterminants of consumption. The chief prediction of the paper''s theoretical results, that noise exactly equals news, is tested using aggregate time series data on consumption and earnings. We find that new earnings information explains only a very small fraction of the variance of aggregate consumption innovations. On the other hand, the extent of suboptimal consumption choice appears to be of little economic significance.

This article examines how the availability of annuities affects savings and inequality in economies in which neither private nor public pensions initially exist. The absence of widespread market or government annuity insurance is clearly descriptive of many less developed countries in the world today; it was also a characteristic of virtually all countries prior to World War II. The paper compares economies with perfect insurance with economies in which completely selfish parents and children pool longevity risk to their mutual advantage. The analysis of the latter economies takes into account the infinite sequence of risk sharing bargains of successive parents with their children. Such bargains affect current risk sharing between parents and child because they determine the welfare of current children when they become parents. Calculations based on the CBS utility function indicate that perfecting annuity insurance can significantly reduce national savings. Indeed, the insurance aspects of government pensions are potentially as important as underfunding government pensions in reducing national savings.

This paper develops a perfect foresight general equilibrium simulation model of life cycle savings that may be used to investigate the potential impact of a wide range of government policies on national savings and economic welfare. The model can provide quantitative answers to a number of long-standing questions concerning the government''s influence on capital formation. These include the degree of crowding out of private investment by debt financed increases in government expenditure, the differential effect on consumption of temporary versus more permanent tax cuts, the announcement effects of future changes in tax and expenditure policy, and the response to structural changes in the tax system, including both the choice of the tax base and the degree of progressivity. The model tracks the values of all economic variables along the transition path from the initial steady state growth path to the new steady state growth path. Hence, it can be used to compute the exact welfare gains or losses for each age cohort associated with tax reform proposals.