浅谈我国死刑制度的限制适用及其发展

2011年判决的陕西＂药家鑫案件＂和云南＂李昌奎案件＂引发了民众对我国死刑制度适用的质疑和讨论。我国的刑法属于重刑法典。＂保留死刑,严格控制死刑＂是我国死刑的基本政策。我国法律在制定的过程中体现了尊重生命、慎用死刑的态度。     

Minimum option prices under decreasing absolute risk aversion

We establish bounds on option prices in an economy where the representative investor has an unknown utility function that is constrained to belong to the family of nonincreasing absolute risk averse functions. For any distribution of terminal consumption, we identify a procedure that establishes the lower bound of option prices. We prove that the lower bound derives from a particular negative exponential utility function. We also identify lower bounds of option prices in a decreasing relative risk averse economy. For this case, we find that the lower bound is determined by a power utility function. Similar to other recent findings, for the latter case, we confirm that under lognormality of consumption, the Black Scholes price is a lower bound. The main advantage of our bounding methodology is that it can be applied to any arbitrary marginal distribution for consumption. This revised version was published online in June 2006 with corrections to the Cover Date.     

On equitable social welfare functions satisfying the Weak Pareto Axiom: A complete characterization

The present paper examines the problem of aggregating infinite utility streams with a social welfare function that respects the Anonymity and Weak Pareto Axioms. The paper provides a complete characterization of domains (of the one period utilities) on which such an aggregation is possible. A social welfare function satisfying the Anonymity and Weak Pareto Axioms exists on precisely those domains that do not contain any set of the order type of the set of positive and negative integers. The criterion is applied to decide on possibility and impossibility results for a variety of domains. It is also used to provide an alternative formulation of the characterization result in terms of the accumulation points of the domain.     

THE EFFECTS OF ECONOMIC REGULATION IN THE ISTANBUL TAXICAB MARKET

This paper discusses the regulation of the Istanbul taxicab market and its consequences. While price and entry regulations are common to many taxi markets, there are significant differences in their institutional frameworks. We examine the problems of the Istanbul market and offer recommendations to improve its efficiency.     

Excess heterogeneity, endogeneity and index restrictions

A discrete or continuous outcome is determined by a structural function in which the effect of some variables of interest is transmitted through a scalar index. Multiple sources of stochastic variation can appear as arguments of the structural function, but not in the index. There may be endogeneity, that is observable and unobservable variables may not be independently distributed. Conditions are provided under which there is local identification of measures of the relative sensitivity of the index to variations in pairs of its possibly endogenous arguments, namely ratios of partial derivatives of the index.     

Sources of exchange rate fluctuations: Are they real or nominal?

I analyze the role of real and monetary shocks on exchange rate behavior using a structural vector autoregressive model of the US vis-à-vis the rest of the world. The shocks are identified using sign restrictions on the responses of the variables to orthogonal disturbances. These restrictions are derived from the predictions of a two-country DSGE model. I find that monetary shocks are unimportant in explaining exchange rate fluctuations. By contrast, demand shocks explain between 21% and 37% of exchange rate variance at 4-quarter and 20-quarter horizons, respectively. The contribution of demand shocks plays an important role but not of the order of magnitude sometimes found in earlier studies. My results, however, support the recent focus of the literature on real shocks to match the empirical properties of real exchange rates.     

Optimal portfolio choice with wash sale constraints

We analytically solve the portfolio choice problem in the presence of wash sale constraints in a two-period model with one risky asset. Our results show that wash sale constraints can heavily affect portfolio choice of investors with unrealized losses. The trading behavior of such investors is to a large extent driven by the desire to realize those losses, either immediately by sharply decreasing the holding of assets carrying unrealized losses, or indirectly by increasing such holdings in order to prepare for a decrease in a future period to earn the tax rebate payment. Our findings are robust to increasing the number of trading dates and introducing a second risky asset and a correlation structure.     

Price clustering on the limit-order book: Evidence from the Stock Exchange of Hong Kong

We examine the clustering pattern in trade and quote prices on the electronic limit order book of the Stock Exchange of Hong Kong (SEHK). Earlier research into clustering focuses on transaction prices only. We study clustering on quote prices over a maximum of five queues on the limit order book. We observe an abnormally high frequency of even and integer prices in trade and quote prices for all tick size groups on the SEHK. The deeper quotes display stronger clustering than the best quotes, indicating that the farther away the quotes are from the best queue, the less information they carry. Our analysis further reveals that an extremely fine tick size itself works as a binding constraint to hinder the price resolution process. We also find that short sale prohibition imposed on the majority of stocks listed on the SEHK causes a significant bias in clustering towards the ask side of the limit order book. This implies that a short sale prohibition impairs efficient price discovery in the market.     

Testable Implications of Pareto Efficiency and Individualrationality

This paper investigates the testable implications of Pareto efficiency and individual rationality on finite data sets in exchange economies with finitely many commodities and agents. Efficiency alone provides no restrictions other than a trivial “no waste”-condition. Efficiency together with individual rationality implies robust restrictionsI appreciate the comments of Don Brown, Truman Bewley and Charles Steinhorn. I also thank seminar participants at Yale, Zuerich and Mainz, as well as conference participants at the 12th European General Equilibrium Workshop in Bielefeld. The generous support of the Cowles Foundation is gratefully acknowledged. The paper also benefited greatly from the comments of an anonymous referee