Using Medicare data for short-run projections of the elderly population.

As the elderly population of the United States grows in absolute number and as a proportion of total population, accurate projections of that population become increasingly important for sound policy decisions. Cohort component techniques are typically used for state and local projections of the elderly population, but are often outdated or even nonexistent for many local areas. This paper suggests an alternative approach, based on Medicare data and simple projection techniques. Projections for several base periods and projection horizons are made for all states and for counties in Florida and are compared with actual Medicare enrollment. On the basis of these comparisons it appears that Medicare data and simple projection techniques can produce very useful short-run projections of the elderly population for states and local areas.     

Issues in the estimation and application of latent structure models of choice

Our paper provides a brief review and summary of issues and advances in the use of latent structure and other finite mixture models in the analysis of choice data. Focus is directed to three primary areas: (1) estimation and computational issues, (2) specification and interpretation issues, and (3) future research issues. We comment on what latent structure models have promised, what has been, to date, delivered, and what we should look forward to in the future.     

On optimality in intergenerational risk sharing

Summary. This paper defines and studies optimality in a dynamic stochastic economy with finitely lived agents, and investigates the optimality properties of an equilibrium with or without sequentially complete markets. Various Pareto optimality concepts are considered, including interim and ex ante optimality. We show that, at an equilibrium with a productive asset (land) and sequentially complete markets, the intervention of a government may be justified, but only to improve risk sharing between generations. If markets are incomplete, constrained interim optimality is investigated in two-period lived OLG economies. We extend the optimality properties of an equilibrium with land and give conditions under which introducing a pay-as-you-go system at an equilibrium would not lead to any Pareto improvement. Received: October 5, 1998; revised version: April 3, 2001     

Länger leben — Siechtum und Pflege ohne Grenzen?

At present, our society and its social security system are not prepared to cope with the challenges resulting from the continuous increase of life expectancy. The traditional concept of disease has to be modified for serving the special needs of the elderly. The optimistic compression of disease theory is an intriguing model, but lacks prove by available data. The anti-aging boom diverts the focus from the social and financial burden that will be unevitably caused by long-term care in the future. If there will not be an — up to now unforeseeable — breakthrough in research, particularly dementia will have an enormous impact on social cost which is often underestimated.     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

Cardinality-based equality of opportunities

We study possible rankings of opportunity profiles. An opportunity profile is a list of opportunity sets, one for each agent in the society. We compare profiles on the basis of the notion of “equality of opportunities”. Our main results show the necessary and sufficient conditions for this comparison to be made using exclusively the information provided by two cardinal measures: the number of common alternatives in all sets of a given profile and the difference between the number of alternatives in the individual sets. We also show that, under additional axioms, we can combine these criteria only in a weighted procedure or in some lexicographic refinements of a weighted procedure.