从比较法的角度谈中国食品安全监管机构的完善

美国、日本、欧盟是世界上公认食品最安全的国家和地区,其进行食品监管的模式一直以政府监管为主,怎么进行监管机构的设置就是需要重点研究的问题。立足于美国、欧盟、日本食品监管机构的设置,讨论我国如何完善食品安全监管机构,通过比较各发达国家机构设置不同得出结论:发达国家食品安全监管机构设置模式分为集中型和分散型,而我国的特有国情导致我国要建立以品种划分的分散型监管模式;风险分析的方法是各国食品安全监管机构采取的食品安全监管的重要手段,风险评估与风险管理的职能由不同的监管机构承担,各监管机关在风险交流的基础上细化各自的职责,注重部门间的协调和统一的组织,能够使食品安全监管机构发挥更大的作用;另外,必须要加重监管机关的责任。     

国家金融安全的杠杆──发展中国家汇率制度的选择

世界金融一体化已成为二十一世纪主要经济特征,并强烈的影响着发展中国家的金融政策,关乎国家金融安全,而选择适当的汇率制度则是解决这一问题的杠杆。本文从时间和空间两个角度出发,历史地比较地分析了发展中国家汇率制度的选择要素、内在结构及其战略取向。     

Endogenous uncertainty and market volatility

We advance the theory that the distribution of beliefs in the market is the most important propagation mechanism of economic volatility. Our model is based on the theory of Rational Beliefs (RB) and Rational Belief Equilibrium (RBE) developed by Kurz (1994, 1997). We argue that the diverse market puzzles which are examined, such as the equity premium puzzle, are all driven by the structure of market expectations. In support of our view, we present an RBE model with which we study financial markets. The model is able to simulate the correct order of magnitude of: (i) the long term mean and standard deviation of the price\dividend ratio; (ii) the long term mean and standard deviation of the risky rate of return on equities; (iii) the long term mean and standard deviation of the riskless rate; (iv) the long term mean equity premium. In addition, the model predicts (v) the GARCH property of risky asset returns; (vi) the observed pattern of the predictability of long returns on assets, and (vii) the Forward Discount Bias in foreign exchange markets. The common economic explanation for these phenomena is the existence of heterogenous agents with diverse but correlated beliefs such that some agents are optimistic and some pessimistic about future capital gains. The model has a unique parameterization under which the model makes all the above predictions simultaneously. The parameterization requires the optimists to be in the majority but the rationality of belief conditions of the RBE require the pessimists to have a higher intensity level. In simple terms, the large equity premium and the low equilibrium riskless rate are the result of the fact that at any moment of time there are agents who hold extreme pessimistic beliefs and they have a relatively stronger impact on the market. The paper also studies the effect of correlation of beliefs among investors. It shows that the main effect of such correlation is on the dynamic patterns of asset prices and returns and is hence important for studying such phenomena as stochastic volatility. Received: May 16, 2000; revised version: November 15, 2000     

Regime switching in stochastic models of commodity prices: An application to an optimal tree harvesting problem

This paper investigates whether a regime switching model of stochastic lumber prices is better for the analysis of optimal harvesting problems in forestry than a more traditional single regime model. Prices of lumber derivatives are used to calibrate a regime switching model, with each of two regimes characterized by a different mean reverting process. A single regime, mean reverting process is also calibrated. The value of a representative stand of trees and optimal harvesting prices are determined by specifying a Hamilton-Jacobi-Bellman Variational Inequality, which is solved for both pricing models using a implicit finite difference approach. The regime switching model is found to more closely match the behavior of futures prices than the single regime model. In addition, analysis of a tree harvesting problem indicates significant differences in terms of land value and optimal harvest thresholds between the regime switching and single regime models.     

商品监管中供方符合性声明模式的应用

对部分WTO成员应用供方符合性声明模式的案例进行了分析,提炼出该模式监管机制的六个关键要素,为我国进出口商品质量安全监管中合理应用供方符合性声明模式提供了参考和建议。     

美国现行宽松货币政策对世界物价的影响——基于不同经济体通货膨胀表现的分析

美国2007年年底开始大幅下调利率,2009年以来又采取了量化宽松的货币政策。与此同时,世界各国,尤其是新兴市场和发展中经济体发生了严重的通货膨胀。虽然美国的宽松货币政策确实提高了2008年以来的通货膨胀率,但是却不能解释新兴市场和发展中经济的通货膨胀普遍高于发达经济体的事实。高通胀的原因仍然在于各国国内的高货币供给。     

Modelling regime shift behaviour in Asian real interest rates

In this paper we investigate whether real interest rates for a number of Asian economies are constant but subject to occasional jumps using the Markov switching technique. We find evidence that all six rates under consideration have generally been stable, only shifting in response to either international or country-specific shocks.     

指令流:外汇市场研究的重要变量

外汇指令流的引入使市场微观结构理论成为近10年来汇率理论发展的一大亮点.令人惊奇的是,外汇指令流不仅在汇率波动和汇率决定研究中非常重要,而且许多传统争议因引进该变量而再次引发经济学家的兴趣,本文致力于介绍西方学术界对该理论的最新运用.     

Forecasting UK GDP growth and inflation under structural change. A comparison of models with time-varying parameters

Evidence from a large and growing body of empirical literature strongly suggests that there have been changes in the inflation and output dynamics in the United Kingdom. The majority of these papers base their results on a class of econometric models that allows for time-variation in the coefficients and volatilities of shocks. While these models have been used extensively for studying evolving dynamics and for structural analysis, there has been little evidence that they are useful for forecasting UK output growth and inflation. This paper attempts to fill this gap by comparing the performances of a wide range of time-varying parameter models in forecasting output growth and inflation. We find that allowing for time-varying parameters can lead to large and statistically significant gains in forecast accuracy.