International trade,risk taking and welfare

This paper shows that the gains from opening up to international trade are smaller when firms do not fully internalize downward risk. I develop a general equilibrium model with two key assumptions. First, when faced with adverse productivity shocks, employers can lay off workers without fully paying the social costs of their layoff decisions, a common feature of many institutions. Second, when opening to international trade, the elasticity of demand perceived by an industry increases. In this setup, I show that international trade induces firms to take more risk and (i) raises the equilibrium unemployment rate, (ii) increases the volatility of sectoral sales and (iii) increases welfare proportionately less than in the absence of the externality. Inducing firms to internalize the costs of layoff (Blanchard and Tirole, 2003) therefore appears even more important in a globalized world.     

人民币实际汇率波动对中欧进出口贸易影响的实证研究

本文通过建立GARCH模型量度了人民币对欧元实际汇率的波动性,并运用协整检验模型、误差修正模型、脉冲响应函数和方差分解技术就人民币实际汇率变动对中国与欧元区之间进出口贸易的影响进行分析。分析结果表明,中国对欧元区出口在长期内随汇率波动而增加,而进口却随汇率波动而减少;在短期内汇率波动推动中国进口,抑制中国出口。人民币升值在长期内给双边出口均造成伤害,但对中国出口伤害更大;在短期内人民币贬值将对中国进出口均有推动作用。本文分析还表明,在长期内,中国对欧元区出口收入效应远远大于欧元区对华出口收入效应;在短期内,中国实际收入变动对欧元区出口表现负向冲击,而欧元区实际收入变动对中国出口表现为正向冲击。中国汇率制度改革对中国出口欧元区产生推动作用,对欧元区出口产生抑制作用,且前者大于后者。实际汇率水平及其波动性变化对欧元区对华出口变动的解释力高于中国实际收入水平变化的解释力,而对于中国对欧元区出口的变动,欧元区实际收入水平变动的解释力高于实际汇率水平及其波动性变化的解释力。     

股票回报率截面离差包含的信息

本文通过实证研究发现，股票回报率的截面离差包含单只股票和组合回报率未来波动的增量信息。而对非预期离差而言，当后期出现高的非预期离差时，伴随的回报率具有惯性，当后期出现低的非预期离差时，伴随的回报率呈现反转现象，这种结论无论对单个公司还是按平均市值分类的组合都是成立的。这些结论对事件研究、期权定价等需要预测价格波动的研究及更好理解价格信息都是有用的，特别在中国股市能更好理解庄家的动机。     

过渡期产业群的演化与政策启示——以浙江永康五金产业群为例

当前我国产业集群正处于过渡时期,市场机制的完善提高了市场交易主体间扩展信任水平,从而降低基于扩展信任的交易费用水平。随着集群规模不断扩大,理性的企业会选择更多地与传统集群外有竞争力的企业进行交易,从导致产业集群由以血缘与亲缘等为纽带的传统集群向基于扩展信任的现代集群演进。本文以浙江永康五金产业群为例对此进行了分析,提出了产业集群发展的几点方略。     

The impact of H-share derivatives on the underlying equity market

We conjecture that an introduction of the Hong Kong Hang Seng Chinese Enterprise Stock Index (H-share Index) futures induces additional speculating activities in the underlying equities, leading to an increase in volatility and volume of the underlying stocks. Whereas, a subsequent introduction of H-share index options increases the level of informed trading and opens up opportunities for speculative and arbitrage activities using futures directly against options. These futures and options trading activities are much cheaper and more efficient than using the underlying stocks, leading to a significant decline in spot market volatility and volume. Our results are consistent with these arguments. We also find that derivative trading does not change the liquidity of H-share constituent stocks. Further tests based on the difference-in-difference approach confirm that the above findings are robust.