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.     

Working While the World Sleeps: A Consideration of Sleep and Shift Work Design

The evolution of society and economic pressure has provided the impetus for operating on a 24-hr basis in many industries. This has occurred with relatively little attention toward sleep deprivation and related problems facing shift workers and the organizations employing them. This paper first documents the move toward shift work and some sleep problems associated with it. We then describe sleep disorders that impact job performance. Next, we describe alternative schedules and give suggestions for shift work implementation. Finally, we offer some normative advice regarding the treatment of shift employees.     

Efficient Liability Rules: Complete Characterization

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

Exchange rate exposure and foreign exchange derivatives: do ineffective hedgers modify future derivatives use?

Recent studies examining the relationship between stock returns and exchange rate changes have provided evidence that the exchange rate exposure of non-financial companies is reduced by the use of foreign exchange derivatives. Building on such research, this study investigates whether past ineffective derivative hedging contributes to explaining future derivatives use. To the extent that companies monitor the effectiveness of their currency risk management practices, past ineffective hedgers can be expected to modify their future use of foreign exchange derivatives accordingly. In our study of 94 non-financial US multinationals, we provide evidence that the change in derivatives use from 1996–1998 to 1998–2000 can be explained in part by the ineffective hedging of currency risk in 1996–1998, controlling for variables associated with theories of optimal hedging. Additional analyses confirm that such primary results are robust to firm size, the level of foreign operations, and the use of derivatives to partially hedge currency risk. Our results imply that as exchange markets and risk management practices change, the use of derivatives to manage exchange rate risk also changes. Our contribution to this field of study is that we find evidence that past ineffective hedgers tend to increase their future use of FXDs.     

Multilateral Reforms of Trade and Environmental Policy

The paper analyzes environmental tax policy reform using a competitive model of world trade that includes production‐generated environmental damage (pollution) and trade tariffs. The authors examine the feasibility of Pareto‐improving multilateral reforms of environmental taxes, and show that any environmental tax reform that is mutually welfare‐improving when compensating lump‐sum transfers are assumed is also welfare‐improving when a suitable tariff reform (but no transfers) is combined with the tax changes. Several specific reform proposals are developed. These results expand the feasible set of mutually improving policy proposals for international policy initiatives.