Estimation in Varying-coefficient Proportional Hazard Regression Model

In this paper, varying coefficient proportional hazard regression models are considered. The model is an important extension of the Cox model, and arises naturally if the coefficients change over different groups characterized by certain covariates in practice. Under random censorship, weighted partial likelihood estimators are defined for the varying coefficients by maximizing weighted partial likelihoods. It is shown that the proposed estimators are consistent and asymptotically normal.     

The structure of authority, federalism, commitment and economic growth

Summary. In a neoclassical growth model with many regions and a mobile factor, two federal arrangements are considered. In the first federal arrangement the central government chooses a uniform tax policy, whereas in the second each regional government chooses its own tax policy. The main result is that the first federal arrangement leads to high tax rates and economic stagnation, whereas the second leads to low tax rates and economic growth. This result stems from a time consistency problem. The lack of tax competition forces a time consistency problem on the central government under the first federal arrangement. In contrast, regional tax competition acts as a commitment device under the second federal arrangement. The fundamental feature in the environment that gives rise to different abilities of the state to commit is the different structure of authority within the state.Received: 10 February 2003, Revised: 2 December 2003, JEL Classification Numbers: H77, O41, E60, C73, E13.Ronald A. Edwards: This is a revision of Chapter 3 of my University of Minnesota Ph.D. I thank my advisor Edward C. Prescott for his encouragement and numerous helpful discussions. I also thank Tim Kehoe for many useful discussions as well as Beth Allen, Berthold Herrendorf, Arilton Teixeira and two anonymous referees for helpful comments. This research was assisted by an International Predissertation Fellowship from the Social Science Research Council and the American Council of Learned Societies with funds provided by the Ford Foundation.     

Asymptotic second-order efficiency of three-stage procedure with a warranted confidence level

This paper considers a three-stage procedure which was proposed by Holm (1995) to yield a fixed-width confidence interval of the normal mean with a precise confidence level. The procedure is shown to be asymptotically second-order efficient. The procedure is also applied to such problems as bounded risk and hypothesis testing     

Recursive risk measures under regime switching applied to portfolio selection

In this paper, we define the conditional risk measure under regime switching and derive a class of time consistent multi-period risk measures. To do so, we describe the information process with regime switching in a product space associated with the product of two filtrations. Moreover, we show how to establish the corresponding multi-stage portfolio selection models using the time consistent multi-period risk measure for medium-term or long-term investments. Take the conditional value-at-risk measure as an example, we demonstrate the resulting multi-stage portfolio selection problem can be transformed into a second-order cone programming problem. Finally, we carry out a series of empirical tests to illustrate the superior performance of the proposed random framework and the corresponding multi-stage portfolio selection model.     

Option exercise with temptation

This paper adopts the Gul and Pensendorfer self-control utility model to analyze an agent’s option exercise decision under uncertainty over an infinite horizon. The agent decides whether and when to do an irreversible activity. He is tempted by immediate gratification and suffers from self-control problems. The cost of self-control lowers the benefit from continuation or stopping and may erode the option value of waiting. When applied to the investment and exit problems, the model can generate the behavior of procrastination and preproperation. In addition, unlike the hyperbolic discounting model, the model here provides a unique prediction. I thank Drew Fudenberg, Bart Lipman, Neng Wang, and participants in the BU theory lunch workshop and in the Canadian Economic Theory Conference 2005 for helpful discussions. I am especially grateful for valuable suggestions from an anonymous referee and coeditor Steve Williamson. The BU ISP Seed Grant has supported this research.     

耕地经营规模对农业生产效率及环境压力的影响研究——以黄淮海地区为例

[目的]基于耕地经营规模效应,考察耕地经营规模对农业生产效率及环境压力的影响,为农业现代化与可持续发展政策制定提供科学依据。[方法]文章通过理论推导与实证检验,从时间序列和横截面2个维度对耕地经营规模与农业生产效率、环境压力的关系进行定量分析。[结果]（1）耕地经营规模对农业生产效率和环境的影响存在不确定性,并非所有区域都存在一致的时空效应。（2）耕地经营规模与单位耕地面积农业机械碳排放、单位耕地面积粮食产量存在明显的负相关关系,这些关系与机械使用效率、技术和劳动力要素投入密切相关。（3）耕地经营规模越小,农业机械使用效率越低,单位耕地面积农业机械碳排放越高;而耕地经营规模增加则会降低化肥、劳动力等要素的投入强度导致农业生产粗放化,进而影响单位耕地面积粮食产量。[结论]农业生产过程中需要构建现代农业产业体系、生产体系和经营体系,降低传统生产要素的投入,不断增加新要素和新技术投入,以实现减碳、增产的双重目标。     

A supermartingale relation for multivariate risk measures

The equivalence between multiportfolio time consistency of a dynamic multivariate risk measure and a supermartingale property is proven. Furthermore, the dual variables under which this set-valued supermartingale is a martingale are characterized as the worst-case dual variables in the dual representation of the risk measure. Examples of multivariate risk measures satisfying the supermartingale property are given. Crucial for obtaining the results are dual representations of scalarizations of set-valued dynamic risk measures, which are of independent interest in the fast growing literature on multivariate risks.     

Update rules for convex risk measures

In the first part of the paper we investigate the properties that describe the intertemporal structure of dynamic convex risk measures. The usual backward approach to dynamic risk assessment leads to strong and weak versions of time consistency. As an alternative, we introduce a forward approach of consecutivity. In the second part we discuss the problem of how to update a convex risk measure when new information arrives. We analyse to what extent the above properties are appropriate update criteria.     

Behavioral consistency in corporate finance: CEO personal and corporate leverage

We find that firms behave consistently with how their CEOs behave personally in the context of leverage choices. Analyzing data on CEOs' leverage in their most recent primary home purchases, we find a positive, economically relevant, robust relation between corporate and personal leverage in the cross-section and when examining CEO turnovers. The results are consistent with an endogenous matching of CEOs to firms based on preferences, as well as with CEOs imprinting their personal preferences on the firms they manage, particularly when governance is weaker. Besides enhancing our understanding of the determinants of corporate capital structures, the broader contribution of the paper is to show that CEOs' personal behavior can, in part, explain corporate financial behavior of the firms they manage.     

农村金融机构竞争实力模型评价研究：以山东省为例

文章构建了农村金融机构竞争实力综合评价指标体系,运用熵值法、灰色关联分析法对硬实力进行评价,运用层次分析法（AHP）对软实力进行测评,同时结合Kendall协同系数检验,对硬实力和软实力测评结果进行一致性检验,最终得出三类机构的竞争实力综合测评结果。通过全面评价农村金融机构的综合竞争实力,为决策者合理制定竞争力策略提供了参考依据。