INTRA-INDUSTRY EFFECTS OF BOND RATING ADJUSTMENTS

Several studies find that bond rating downgrades cause negative valuation effects. Other studies find that signals conveyed by earnings releases, earnings forecasts, bankruptcies, and stock offerings of individual firms can be transmitted to their corresponding industries. By combining the two sets of studies, we hypothesize that bond rating changes may contain relevant information not only about the firm, but also about the corresponding industry. We find significantly negative valuation effects for rating downgrades, which are transmitted throughout the industry. Furthermore, we find that intra-industry effects depend on particular characteristics of the bond downgrade, the downgraded firm, and industry rivals. Specifically, the negative intra-industry effects are more pronounced when (1) the downgraded firm experiences a more severe share price response to the bond rating downgrade, (2) the downgraded firm is dominant in the industry, (3) the downgraded firm is more closely related to its rivals in the industry, and (4) the downgrade is due to a deterioration in the firm's financial prospects.     

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.