SHORT‐RUN POLICY COMMITMENT WHEN INVESTMENT TIMING IS ENDOGENOUS: ‘MORE HARM THAN GOOD?’

In our model, firms choose when to set cost‐reducing investment and the government, which only has short‐run commitment power, sets an output subsidy. We show that firms that delay investment without government intervention have an incentive to invest early under policy activism, strategically underinvesting or overinvesting to obtain larger subsidies. The policy scheme thus creates a new, potentially more harmful, distortion. Under oligopoly, a firm has a weaker incentive to manipulate policy than under monopoly, which makes policy intervention less harmful. We investigate when the government may do better by adhering to laissez‐faire than by engaging in active policy intervention.     

Delays and equilibria with large and small information in social learning

The general model of social learning with irreversible investment and endogenous timing is analyzed for any distribution of private informations. Strategic complementarities and multiple equilibria appear which are generated solely by information externalities. Different equilibria generate strikingly different amounts of information. The impacts of various assumptions (bounded beliefs, large number of agents, discrete time and short periods) are examined carefully. The properties are robust to the introduction of observation noise with a continuum of agents.     

The welfare costs of unreliable water service

Throughout the developing world, many water distribution systems are unreliable. As a result, it becomes necessary for each household to store its own water as a hedge against this uncertainty. Since arrivals of water are not synchronized across households, serious distributional inefficiencies arise. We develop a model describing the optimal intertemporal depletion of each household's private water storage if it is uncertain when water will next arrive to replenish supplies. The model is calibrated using survey data from Mexico City, a city where many households store water in sealed rooftop tanks known as tinacos. The calibrated model is used to evaluate the potential welfare gains that would occur if alternative modes of water provision were implemented. We estimate that most of the potential distributional inefficiencies can be eliminated simply by making the frequency of deliveries the same across households which now face haphazard deliveries. This would require neither costly investments in infrastructure nor price increases.     

Implementation of college admission rules

Summary We consider both Nash and strong Nash implementation of various matching rules for college admissions problems. We show that all such rules are supersolutions of the stable rule. Among these rules the lower bound stable rule is implementable in both senses. The upper bound Pareto and individually rational rule is strong Nash implementable yet it is not Nash implementable. Two corollaries of interest are the stable rule is the minimal (Nash or strong Nash) implementable solution that is Pareto optimal and individually rational, and the stable rule is the minimal (Nash or strong Nash) implementable extension of any of its subsolutions.We wish to thank Professor William Thomson for his efforts in supervision as well as his useful suggestions. We are grateful to the participants in his reading class, workshops at Bilkent University, University of Rochester, and in particular Jeffrey Banks, Stephen Ching, Bhaskar Dutta, Rangarajan Sundaram and an anonymous referee for their helpful comments.     

Stochastic growth: a duality approach

We re-examine the representative agent's optimal consumption and savings under uncertainty in the presence of investment constraints using martingale representation and convex analysis techniques. This framework allows us to explicitly quantify precautionary savings which induces a higher average growth rate than in a certainty setup. We provide a closed form solution for a Cobb-Douglas economy. The effect of uncertainty on portfolio selection is analyzed. Consumption growth rate and risk free interest rate exhibit a U-shaped relationship. Uncertainty negatively affects expected consumption growth rate; such a result seems to be supported by empirical evidence.     

跨国医药企业境外分支机构的研发活动概况

本文对全球医药企业境外分支机构开展研发活动的总体情况,以及跨国医药企业海外研发机构的情况进行综合分析。     

Commodity price inflation, retail pass-through and market power

When commodity prices rise, wholesalers and retailers of products derived from basic commodities respond by passing along at least a portion of the price increase to consumers. In this paper we examine whether firms respond differently to positive commodity price shocks than to negative commodity price shocks; that is, whether commodity price volatility alters market power. We exploit recent volatility in food commodity prices over the period 2007-2010 to investigate how commodity price shocks translate into market power in two different vertically-structured food product industries: potatoes and fluid milk. For potatoes, we find both wholesale and retail market power decreases (increases) during periods of rising (falling) commodity prices. Moreover, price-cost margins widen a substantially greater degree in response to negative shocks than margins narrow in response to positive shocks, indicating that commodity price volatility increases market power. For fluid milk, we find that market power likewise declines during periods of rising commodity prices; however, market power does not significantly change during periods of falling commodity prices, suggesting that commodity price volatility decreases market power.     

Private Pension Arrangements and Retirement in Britain*

This paper looks at the policy debate surrounding private pensions and retirement patterns in the UK. Recent increases in longevity have led not only to increased pressures in public pensions but also to corresponding increases in the importance of private pensions in the UK and changes in the way in which they are structured. We consider the economic implications of these changes, and in particular the increased importance of defined contribution plans. In addition, we discuss the prospects for future trends in retirement ages.     

Full-cost pricing in the classical competitive process: A model of convergence to long-run equilibrium

In the last 10–15 years a lot of attempts has been devoted to study the calssical process of convergence of market prices toward natural prices. The two forces that one has thought could achieve this target were capital mobility, that determines the dynamics of output, and demand-supply forces, that determine the dynamics of prices. In this article a model of classical competition is proposed in which a full-cost pricing mechanism is adopted in the rule of evolution of market prices. An asymptotical stability result of long-run equilibrium is proved for a two-commodity model with and without a final demand.     

Representative consumer's risk aversion and efficient risk-sharing rules

We study the representative consumer's risk attitude and efficient risk-sharing rules in a single-period, single-good economy in which consumers have homogeneous probabilistic beliefs but heterogeneous risk attitudes. We prove that if all consumers have convex absolute risk tolerance, so must the representative consumer. We also identify a relationship between the curvature of an individual consumer's individual risk sharing rule and his absolute cautiousness, the first derivative of absolute risk-tolerance. Furthermore, we discuss some consequences of these results and refinements of these results for the class of HARA utility functions.