of Airport Landing Slots

Abstract: We investigate the competitive effects of exchanges or sales of airport landing slots. In our model, airlines with potentially asymmetric slot allocations must decide upon which routes to use their landing slots. When all airlines serve the same routes in a slot-constrained Cournot-Nash equilibrium, small changes in slot allocations among airlines do not affect the overall allocation of slots across routes or air fares. In a symmetric equilibrium where slot-holding airlines have the same number of slots, we find that an increase in the number of slot-holding airlines leads to higher social welfare and consumer surplus, although the number of served routes may decline. Under asymmetric slot allocations, larger slot holders serve “thin” demand routes that are not served by smaller slot holders. In this situation, transfers of slots from larger to smaller slot holders increase social welfare and consumer surplus, even though fewer routes may be served. More generally, our results suggest that increases in slot concentration are harmful to consumers and social welfare, although consumers on relatively thin routes may gain air transportation service as a result.

Perceived neighborhood safety and incident mobility disability among elders: the hazards of poverty

<p>Abstract</p> <p>Background</p> <p>We investigated whether lack of perceived neighborhood safety due to crime, or living in high crime neighborhoods was associated with incident mobility disability in elderly populations. We hypothesized that low-income elders and elders at retirement age (65 – 74) would be at greatest risk of mobility disability onset in the face of perceived or measured crime-related safety hazards.</p> <p>Methods</p> <p>We conducted the study in the New Haven Established Populations for Epidemiologic Studies of the Elderly (EPESE), a longitudinal cohort study of community-dwelling elders aged 65 and older who were residents of New Haven, Connecticut in 1982. Elders were interviewed beginning in 1982 to assess mobility (ability to climb stairs and walk a half mile), perceptions of their neighborhood safety due to crime, annual household income, lifestyle characteristics (smoking, alcohol use, physical activity), and the presence of chronic co-morbid conditions. Additionally, we collected baseline data on neighborhood crime events from the New Haven Register newspaper in 1982 to measure local area crime rates at the census tract level.</p> <p>Results</p> <p>At baseline in 1982, 1,884 elders were without mobility disability. After 8 years of follow-up, perceiving safety hazards was associated with increased risk of mobility disability among elders at retirement age whose incomes were below the federal poverty line (HR 1.56, 95% CI 1.02 – 2.37). No effect of perceived safety hazards was found among elders at retirement age whose incomes were above the poverty line. No effect of living in neighborhoods with high crime rates (measured by newspaper reports) was found in any sub-group.</p> <p>Conclusion</p> <p>Perceiving a safety hazard due to neighborhood crime was associated with increased risk of incident mobility disability among impoverished elders near retirement age. Consistent with prior literature, retirement age appears to be a vulnerable period with respect to the effect of neighborhood conditions on elder health. Community violence prevention activities should address perceived safety among vulnerable populations, such as low-income elders at retirement age, to reduce future risks of mobility disability.</p

Quality Choice, Trade Policy, and Firm Incentives.

Quality choice is examined in a duopoly with one foreign and one domestic firm where consumers have similar preferences for quality but different preferences for brands. Firms make quality commitments prior to choosing price and policy intervention assumes several forms. The policy conclusions depend on whether firms face "set-up" costs in raising product quality. In the absence of set-up costs, both domestic and foreign firms make socially optimal quality choices. In the presence of set-up costs, the foreign firm, and often the domestic firm, sets quality below the socially optimal level. Incomplete information alters these conclusions, however. Copyright 1992 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

Antidumping Policy.

When an antidumping policy involves the imposition of duties, the threat of antidumping enforcement may alter strategic behavior under imperfect competition. This point is illustrated in a model where the foreign firm is a monopolist in its local market but competes with a domestic firm in the home country's market. The welfare effects of an antidumping policy are examined under quantity-setting and price-setting behavior with either perfect or imperfect substitutes. Imposing an antidumping policy frequently improves domestic welfare under quantity-setting behavior and typically worsens it under price-setting behavior. Surprisingly, foreign welfare may improve. Copyright 1993 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

The Impact of Quotas and Tariffs on Strategic R&D Behavior.

Quotas and tariffs are compared in a two-stage Cournot duopoly game where R&D is chosen initially and output is selected subsequently. Imposing a quota at or below the free-trade import level results in either a pure-strategy or a mixed-strategy equilibrium. Compared to an equally restrictive tariff, a quota leads to higher domestic profits, but lower domestic output and R&D (in a pure-strategy equilibrium). Furthermore, a quota and a tariff may often produce opposite effects on domestic R&D. A quota set above the free-trade import level may become binding and may lead to multiple equilibria. Copyright 1991 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.