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。     

Real options and contingent convertibles with regime switching

We consider a firm with no assets in place but an option to invest in a project. The investment is irreversible but delayable in a regime-switching economy. The firm issues equity, straight bonds (SBs) and contingent convertibles (CoCos). We provide the closed-form prices for the firm׳s securities and the pricing and timing of the option. Our numerical analyses discover that issuing CoCos instead of SBs induces much less agency cost of debt. The agency cost is higher in a boom economy than in recession but the difference is small. There is a unique CoCos׳ conversion ratio such that the agency cost arrives at the minimum value zero. The inefficiencies arising from asset substitution and debt overhang are much more significant in recession than in boom. Only if the conversion ratio is not too small, the two inefficiencies disappear during boom periods. While the effects of the conversion rate on optimal capital structure and firm value and those of supervision and jump intensity on optimal CoCos׳ coupon are ambiguous and weak, the stricter the supervision or the longer the economy remains in recession, the less the option value and the optimal SBs׳ coupon.     

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.     

How much is the gap?—Efficient jump risk-adjusted valuation of leveraged certificates

This paper develops a novel and highly efficient numerical algorithm for the gap risk-adjusted valuation of leveraged certificates. The existing literature relies on Monte Carlo simulations, which are not fast enough to be used in a market-making environment. This is because issuers need to compute thousands of price updates per second. By valuing leveraged certificates as multi-window barrier options, we explicitly model random jumps that occur at known times, such as between the exchange closing and re-opening. Our algorithm combines the one-day transition probability with Simpson’s numerical integration rule. This yields a backward induction scheme which requires a significantly coarser spatial and time grid than finite-difference methods. We confirm its robustness and accuracy through Monte Carlo simulations.     

Interest rate dynamic effect on stock returns and central bank transparency: Evidence from emerging markets

Interest rate dynamic effect on stock returns is examined under different levels of central bank transparency under an asset pricing context. Using a large set of emerging countries in a panel data framework, we provide evidence for a negative link between stock returns and interest rate differences. However, this negative effect is reduced significantly under a transparent central bank, underlying a non-linear impact on stock returns. Our study is focused on a period from 1998 to 2008 where fundamental changes in the level of central banks’ transparency were occurred. Our findings imply that restrictive monetary policies under high levels of transparency lead to smoother reductions on stock returns with significant benefits for financial stability.     

Geometric Asian option pricing in general affine stochastic volatility models with jumps

In this paper, we present some results on Geometric Asian option valuation for affine stochastic volatility models with jumps. We shall provide a general framework into which several different valuation problems based on some average process can be cast, and we shall obtain closed form solutions for some relevant affine model classes.     

Herding behavior in the Pakistan stock exchange: Some new insights

This study attempts to examine the presence of herding behavior in the Pakistan Stock Exchange (PSX). The novel contribution of this paper is that it investigates the herding phenomenon from a large number of facets such as herding of firms towards market, herding of firms towards industry portfolios, herding of industry portfolios towards market, herding in mostly traded stocks and in large and small stocks, and herding in the crisis period. For this purpose, we use the herding behavior model of Christie and Huang (1995) on the daily closing prices data of 609 firms listed on the PSX from January 2004 to December 2013. Results show that individual firms do not herd towards market index, except when the market experiences a negative return of 5%. However, when we sort firms into small and large groups based on median market capitalization, results indicate that large firms show herding behavior in extreme market movements. Further, we find that firms in several industries herd towards their industry portfolios. However, we find weak evidence of industry portfolios herding towards the market. We also segregate the impact of financial crisis of 2008 from normal times. These findings support results of our baseline estimation.