东部地区农业结构变动与政策变量之间的相关性研究

本文通过农民收入变量、农民受教育程度、农村人均固定资产投资额、政府用于农村人均文教娱乐用品及服务支出和政府用于农村财政支出等政策变量与东部地区农业结构变动的相关性分析,再根据未来若干年我国及东部地区农业政策变化趋势,从而预测未来我国东部地区农业结构的变化趋势。     

QUADRATIC TERM STRUCTURE MODELS FOR RISK-FREE AND DEFAULTABLE RATES

In this paper, quadratic term structure models (QTSMs) are analyzed and characterized in a general Markovian setting. The primary motivation for this work is to find a useful extension of the traditional QTSM, which is based on an Ornstein–Uhlenbeck (OU) state process, while maintaining the analytical tractability of the model. To accomplish this, the class of quadratic processes, consisting of those Markov state processes that yield QTSM, is introduced. The main result states that OU processes are the only conservative quadratic processes. In general, however, a quadratic potential can be added to allow QTSMs to model default risk. It is further shown that the exponent functions that are inherent in the definition of the quadratic property can be determined by a system of Riccati equations with a unique admissible parameter set. The implications of these results for modeling the term structure of risk-free and defaultable rates are discussed.     

Symmetry and order in the portfolio allocation problem

Summary. This research studies the role of multivariate distribution structures on random asset returns in determining the optimal allocation vector for an expected utility maximizer. All our conclusions pertain for the set of risk averters. By carefully disturbing symmetry in the distribution of the, possibly covarying, returns, we ascertain the ordinal structure of the optimized allocation vector. Rank order of allocations is also established when a permutation symmetric random vector is mapped into the returns vector through location and scale shifts. It is shown that increased dispersion in the vectors of location and scale parameters benefit, ex-ante, investors as does a decrease in the rank correlation coefficient between the location and scale parameter vectors. Revealed preference comparative static results are identified for the location and scale vectors of asset returns. For most issues addressed, we arrive at much stronger inferences when a safe asset is available. Received: August 8, 2000; revised version: January 8, 2001     

Temporary controls on capital inflows

During the past decade a number of countries imposed capital controls that had two distinguishing features: they were asymmetric, in that they were designed principally to discourage capital inflows, and they were temporary. This paper studies formally the consequences of these policies, calibrates their potential effectiveness, and assesses their welfare implications in an environment in which the level of capital inflows can be sub-optimal. In addition, motivated by the fact that these types of controls have often been left in place after the dissipation of the shock that lead to the controls being implemented, the paper evaluates the welfare cost of procrastination in removing these types of controls.     

Sterilization of short-term capital inflows—through lower interest rates?

Reductions in international interest rates are a major cause of capital flows to emerging economies. Increases in domestic interest rates are a frequent policy response to the resulting price increases. This is often unsuccessful. The paper suggests a theoretical explanation based on distinctive features of emerging financial markets, including imperfect asset substitutability and imperfect capital mobility for some sectors of the economy. It concludes that the appropriate policy response to capital inflows may be lower interest rates.     

Money, endogenous fertility and economic growth

This paper analyzes the issue of money superneutrality through an intertemporal optimizing model of capital accumulation with endogenous fertility, i.e. endogenous population growth. Two elements of this setup invalidate money superneutrality: (i) a demand for fertility that depends on real money balances, and (ii) an inverse relation between capital–labor ratio and population growth. Higher monetary growth increases fertility, since it reduces its opportunity cost, and hence diminishes capital intensity, and per capita output. This reverse Tobin effect is matched by an increase in aggregate capital and output growth rates. In this framework, the optimal monetary growth rule is a “distorted Friedman rule”.     

马克思如何实现对黑格尔辩证法的改造

马克思是如何实现对黑格尔辩证法的唯物主义改造的呢?马克思反复强调,黑格尔哲学是一种“头足倒置”的哲学,通过推敲黑格尔和马克思的辩证法思想,本文认为马克思实现对黑格尔辩证法的改造,至少经过了三个倒置:倒置了黑格尔辩证法辩证发展的主体;倒置了黑格尔辩证法辩证发展的中介;倒置了黑格尔辩证法辩证发展的理论结构。     

我国资本市场存在的制度功能缺陷与对策

我国资本市场是在新旧体制转换中建立起来的，先天就存在着制度和市场功能方面的缺陷，亟需要采取有效应对策略以弥补，使我国资本市场的发展走上正常轨道。     

Stability and Segregation in Group Formation

This paper presents a model of group formation based on the assumption that individuals prefer to associate with people similar to them. It is shown that, in general, if the number of groups that can be formed is bounded, then a stable partition of the society into groups may not exist. (A partition is defined as stable if none of the individuals would prefer be in a different group than the one he is in.) However, if individuals' characteristics are one-dimensional, then a stable partition always exists. We give sufficient conditions for stable partitions to be segregating (in the sense that, for example, low-characteristic individuals are in one group and high-characteristic ones are in another) and Pareto efficient. In addition, we propose a dynamic model of individual myopic behavior describing the evolution of group formation to an eventual stable, segregating, and Pareto efficient partition. Journal of Economic Literature Classification Numbers: C72, H41.