信息不对称、过度自信与股价变动

信息传导的非同步和投资者情绪变化是股票市场的两个典型特征,前者会引发投资者之间出现信息不对称问题,后者主要体现为投资者过度自信,两者共同作用影响股票价格变动。本文将信息不对称和投资者过度自信情绪置于同一个分析框架,建立两阶段动态序贯定价理论模型研究现实市场上信息传导过程中股价变动的内在机制。结果表明:(1)面临新信息的进入,投资者对股票收益预期的调整与均衡价格之间具有正相关关系;(2)面临有利消息时,过度自信投资者比例越大,股票的均衡价格越高,投资收益将越低;面临不利消息时则相反;(3)随着过度自信投资者比例以及过度自信程度升高,市场风险溢价将下降;(4)投资者群体在信息传导过程中出现分化,对股价变动形成异质信念,未获取信息和获取信息但未出现过度自信的投资者认为股价被高估,获取信息且出现过度自信的投资者认为价格被低估,促使更多的交易,引发市场成交量和股价变动;(5)过度自信投资者比例与过度自信程度提高均会对市场效率产生正向影响,而对市场深度具有负向效应。最后,基于理论结果对非对称性和持续性等典型的市场波动性特征进行解释。     

The effects of economic growth on income inequality in the US

The paper analyzes the relation between growth and income inequality in the US during the post-war years (1953–2008). We show that the income of the top income groups is more sensitive to growth, defined broadly as current growth and changes in expectations of future growth, compared to the income of the lower income groups. We provide evidence that this increased sensitivity arises for two reasons: (a) the top income groups receive a large portion of their income from wealth, which is more sensitive to growth than labor income and (b) the top income groups receive a large portion of their labor income in the form of pay-for-performance (equity compensation), which is also sensitive to growth. Consequently, we conclude that growth and income inequality are positively associated.     

股权性质、环境不确定性与技术资本配置效率

技术转化为资本，资本创造价值已经成为共识，技术资本在不同公司创造价值的作用程度不同，根源是技术资本配置效率问题。选取沪深两市2008-2013年间制造业上市公司为样本，检验了基于不同股权性质的公司环境不确定性对企业技术资本配置效率和价值的影响，研究结果表明：①企业环境不确定性程度越高，技术资本配置效率越低，并且技术资本配置偏离度在国有公司中表现为配置过度，在非国有公司表现为配置不足；②在股权性质为国有的公司中，由环境不确定性引发的技术资本配置偏离将降低企业价值，在非国有控股公司中，由环境不确定性导致的技术资本配置偏离将增加企业价值。     

Behavioral determinants of supply chain integration and coexistence

Economic theory considers physical production characteristics and related property rights as key determinants of the organization of an industry. Yet, we frequently observe coexisting governance modes within industries and firms, even when the transaction attributes of a commodity are homogenous. We test whether risk and time preferences, price expectations, and trust in supply chain types can explain variations and coexistence in governance. Specifically, we experimentally elicit economic preferences of forest managers in the Swiss wood sector. We find that all behavioral dimensions are related to the choice of sales channel. Most importantly, trust and expectations are key determinants in transferring property rights, while risk aversion, patience, and ownership structure explain the existence of plural forms at the firm level.     

Impact of interest rate surprises on Islamic and conventional stocks and bonds

This paper studies the impact of interest rate news surprises on Islamic and conventional stock and bond indices, using a dataset which covers interest rate announcements and forecasts, as well as stock and bond indices in three Islamic and eight non-Islamic countris. We find that interest rate surprises tend to have a smaller impact on the returns and volatility of Islamic than conventional bonds because Islamic bonds are structured to avoid explicit interest rates. However, interest rate surprises have about the same or bigger impact on the returns and volatility of Islamic relative to conventional stocks, despite the low amounts of cash and debt holdings of firms comprising Islamic stock indices.     

Stock exchange mergers and market efficiency

The aim of this article is to examine the impact of stock exchange mergers on the degree of informational efficiency. For this purpose, we apply the generalized spectral shape test for the martingale difference hypothesis to the stock returns before and after the 31 domestic and cross-border mergers completed from 1997 to 2011. The test is conducted with moving subsample windows, allowing us to detect the periods of (in)efficiency, and thus to conduct a comparative analysis for pre-merger and post-merger periods. We find that higher levels of efficiency are less frequent than lower levels of efficiency after a stock exchange merger. We also find that the impact on the level of efficiency depends on a range of merger characteristics such as the level of development, size, geographical diversification and industrial diversification of stock exchange.     

Stock price synchronicity to oil shocks across quantiles: Evidence from Chinese oil firms

This paper investigates behaviour of stock price synchronicity to oil shocks across quantiles for Chinese oil firms. The spillover effects of the oil market on a firm are segregated into firm-specific and market-wide information. First, our results report a higher level of synchronicity by dynamic conditional correlations than by R-square since the former better captures dynamic linear dependence. Second, we find strong evidence of size effect. In particular, stock price synchronicity is generally higher in large-cap firms than in small-cap ones. Oil shocks affect synchronicity in the upper quantiles differently based on firm size. Third, we also find that synchronicity responds to oil shocks significantly in extreme low quantiles, implying that shocks in the oil market are transmitted to Chinese oil firms via firm-specific information. Finally, we determine that oil shocks have little or no immediate impact on stock price synchronicity; instead, cumulative lagged effect is evident. This evidence highlights the lagging effect of spillover of oil shocks on Chinese oil firms.     

Islamic equity market integration and volatility spillover between emerging and US stock markets

The purpose of this paper is to study the conditional correlations across the US market and a sample of five Islamic emerging markets, namely Turkey, Indonesia, Pakistan, Qatar, and Malaysia. The empirical design uses MSCI (Morgan Stanley Capital International) Islamic equity index since it applies stringent restrictions to include companies. Indeed, two main restrictions must be met: (i) the business activity must be compliant with Shari’ah (i.e., Islamic law) guidelines and (ii) interest-bearing investments and leverage ratios should not exceed upper limits. Three models are used: multivariate GARCH BEKK, CCC, and DCC. The estimation results of the three models show that the US and Islamic emerging equity markets are weakly correlated over time. No sheer evidence supports that the US market spills over into the Islamic emerging equity markets. Besides interpreting the results in terms of weak market integration, the peculiar specificities of the Islamic finance industry and the admittance conditions to the MSCI Islamic equity index contribute to explaining them. Indeed, Islamic finance bans interest-bearing investments and imposes some rules, such as asset-backing, which has sizeable impacts on volatility spillover and shocks transmissions, alongside with the close linkage between real and financial sectors. These findings suggest that investors should take caution when investing in the Islamic emerging equity markets and diversifying their portfolios in order to minimize risk.     

Financial markets with volatility uncertainty

We investigate financial markets under model risk caused by uncertain volatilities. To this end, we consider a financial market that features volatility uncertainty. We use the notion of G-expectation and its corresponding G-Brownian motion recently introduced by Peng (2007) to ensure a mathematically consistent framework. Our financial market consists of a riskless asset and a risky stock with price process modeled by geometric G-Brownian motion. We adapt the notion of arbitrage to this more complex situation, and consider stock price dynamics which exclude arbitrage opportunities. Volatility uncertainty results in an incomplete market. We establish the interval of no-arbitrage prices for general European contingent claims, and deduce explicit results in the Markovian case.     

Small farmer cooperatives and voluntary coffee certifications: Rewarding progressive farmers of engendering widespread change in Costa Rica?

Our research examines the benefits and drawbacks for cooperatives who participate in voluntary coffee certifications. We interviewed administrators at twenty Costa Rican coffee cooperatives about management practices related to voluntary certification. Voluntary certifications are popular among coffee cooperatives. Access to certified markets is facilitated by state support of the cooperative sector, regulation of the coffee sector and well-enforced environmental and social laws. However, there are no significant or consistent financial incentives for farmers to pursue certification. Multiple certifications may lower auditing and implementation costs, but cooperatives rarely receive the full premium for multiply-certified coffee. Low market demand for certified coffee, weak price incentives and high auditing and management costs encourage cooperatives to certify only a portion of their members. This strategy rewards compliant farmers rather than inducing widespread change to farming practices among the entire membership. Though financial incentives are weak, certifications offer non-financial benefits to both farmers and cooperatives, including better management and more resilient cooperatives.