Ugo Broggi: a precursor in mathematical economics

The concern for the existence of solution to the Walras - Cassel model is usually dated at the beginning of the 1930s, and one decade later the proof of existence of utility function. Ugo Broggi, however, posed both issues in 1923 and 1919, respectively, and even hinted at modern ways of solving them. He was an outstanding mathematician, a former disciple of David Hilbert and collaborator with the Giornale degli Economisti. Broggi's achievements are also linked to a critical reading of Osorio's treatise on Paretian economics.     

人民币实际汇率水平的合理性评估:1994—2008

本文基于行为均衡汇率模型,采用1994年第1季度-2008年第2季度的时序数据样本,运用自回归分布滞后模型测算了人民币均衡实际汇率,并对人民币实际汇率的合理性进行了评估.分析结果表明,经济基本面因素能较好地拟合人民币实际汇率的变化过程;人民币实际汇率经历了三次低估和三次高估,但失调程度并不严重.     

博弈论视角下公估人的理性选择及外部约束

保险公估人是保险业发展不可缺少的重要组成部分,但“公估不公”始终是公估行业发展中的一个难题。作为一种典型的承揽关系,保险人与公估人之间存在着信息不对称,以及由此带来的道德风险。本文从博弈论的角度,构建公估人和保险人之间的策略型博弈,通过求解纳什均衡发现,公估人的理性选择并不总是诚实公正。因此,只有加强外部约束,才能实现...     

资本账户开放与国际金融冲击的传导*——基于DSGE模型的分析

本文在动态随机一般均衡的框架下，建立了一个包括贸易部门和非贸易部门的小型开放经济模型，系统研究和比较资本管制与资本账户开放两种情况下，国外金融冲击、出口需求冲击对中国经济的不同影响和传导机制，并检验资本账户开放情形下应对国际冲击时不同货币政策规则的有效性。结果发现：当资本账户开放时，一国受到国外冲击的波动幅度远大于资本管制的情况；资本管制和资本账户开放对国际金融冲击传导机制的关键差异在于贸易部门与非贸易部门的互动关系，具体表现为劳动力转移的差异；在资本账户开放后，面对不同形式的国际冲击，货币数量型规则和混合型规则均能有效熨平经济波动。     

玉米补贴政策调整对宏观经济的影响*——基于CGE模型的分析

[目的]寻求玉米补贴政策改变对宏观经济和粮食安全的影响,并厘清影响的幅度,寻求玉米政策调整的合理方向。[方法]对现有的中国可计算一般均衡模型进行了改进,引入库存积累、临时存储库存入市、库存销售和顺价机制,加入玉米实物量模块。通过设定政策模拟情景,运用2012年中国投入产出表、农业农村部、中国统计年鉴等资料将数据库进行了更新,对农业部门的玉米补贴减少政策的影响进行了模拟。[结果]降低玉米种植补贴后,玉米种植面积和产量都将改变。短期内,补贴减少将减少财政压力。中长期来看,减少补贴政策将对GDP产生负面影响,且远大于财政补贴减少的幅度。而玉米占经济量的份额很小,玉米相关行业的变化,对宏观经济的影响较弱。[结论]实现去库存、调结构、降低种植面积,进行市场化决策,就要坚持玉米价格市场化改革,注重政策的时效性和针对性,加强信息监测预警。提高政府对玉米市场的宏观调控能力,实施多策并举的政策,有助于实现宏观经济改善,保持农业生产持续健康良好运行。     

Nonrecursive separation of risk and time preferences

Recursive utility disentangles preferences with respect to time and risk by recursively building up a value function of local increments. This involves certainty equivalents of indirect utility. Instead we disentangle preferences with respect to time and risk by building up a value function as a non-linear aggregation of certainty equivalents of direct utility of consumption. This entails time-consistency issues which are dealt with by looking for an equilibrium control and an equilibrium value function rather than a classical optimal control and a classical optimal value function. We characterize the solution in a general diffusive incomplete market model and find that, in certain special cases of utmost interest, the characterization coincides with what would arise from a recursive utility approach. But also importantly, in other cases, it does not: The two approaches are fundamentally different but match, exclusively but importantly, in the mathematically special case of homogeneity of the value function.     

Slow-moving capital and stock returns

This paper studies the effects that delay in capital allocations in the stock market and high short-term trading incentives have on returns of this market. We report that capital inertia makes the Sharpe ratio and the volatility of the stock returns many times higher than in an economy with no capital delays. Furthermore, in agreement with empirical literature, the stock price displays short-term overreaction and high volatility of the conditional Sharpe ratio.     

Regime shift,speculation, and stock price

We investigate the impacts of speculation on stock price and return volatility in a framework with regime shifting. We find that greater difference in beliefs about the probability of bad state leads to higher stock prices. The intuition is that in periods of higher dispersion of beliefs, the investors perceive greater speculative opportunities, leading to increased demands and valuations of the stock. When investors agree with each other on the state of dividend growth, they have a stronger incentive to invest in the riskless bond, when becoming more pessimistic about the dividend growth. As a result, the demand and the valuations of stock decrease. Moreover, higher level of heterogeneity in beliefs gives rise to higher volatility of the stock returns, even in the absence of dividend shocks. Furthermore, with homogeneous beliefs, return volatility with respect to investors’ beliefs follows an inverted-U shape.     

The computable general equilibrium analysis of the reduction in tariffs and non-tariff measures within the Korea-Japan-European Union free trade agreement

The trilateral Korea-Japan-EU FTA with the removal of tariffs can contribute to the increase GDPs of Korea, Japan, and the EU. The reduction of NTMs gives more benefits from the Korea-Japan-EU FTA. In particular, trilateral Korea-Japan-EU FTA with the reduction of both import tariffs and NTMs can give the larger increases in Korea, Japan and the EU’s GDPs, exports, and imports. Furthermore, the Korea-Japan-EU FTA also provides the positive welfare effects to all participating countries such as Korea, Japan the EU. And it can also contribute to increase the whole world’s welfare level. Thus, the Korea-Japan-EU FTA will be a win-win FTA strategy not only to Korea, Japan, and EU but also to the global world.     

Simple Markovian equilibria in dynamic spatial legislative bargaining

The paper proves, by construction, the existence of Markovian equilibria in a dynamic spatial legislative bargaining model. Players bargain over policies in an infinite horizon. In each period, a sequential protocol of proposal-making and voting, with random proposer recognitions and a simple majority, produces a policy that becomes the next period's status-quo; the status-quo is endogenous. The construction relies on simple strategies determined by strategic bliss points computed by the algorithm we provide. A strategic bliss point, the dynamic utility ideal, is a moderate policy relative to a bliss point, the static utility ideal. Moderation is strategic and germane to the dynamic environment; players moderate in order to constrain the future proposals of opponents. Moderation is a strategic substitute; when a player's opponents do moderate, she does not, and when they do not moderate, she does. We provide conditions under which the simple strategies induced by the strategic bliss points computed by the algorithm deliver a Stationary Markov Perfect equilibrium, and we prove its existence in generic games with impatient players and in symmetric games. Because the algorithm constructs all equilibria in simple strategies, we provide their general characterization, and we show their generic uniqueness.