基于动态内生性的董事会结构与公司绩效间的跨时期相互作用

在董事会结构与公司绩效间关系的研究中,动态内生性问题通常被忽略。本文以2002-2011年410家上市公司为样本,在动态内生性的框架下,运用动态面板的System GMM估计方法,研究了董事会结构与公司综合绩效间的关系。结果表明：董事会结构与公司绩效间存在动态内生性问题,当期董事会结构与公司绩效没有显著的相关性,前期的董事会结构与公司绩效间存在显著的正相关关系,且前期公司绩效对当期董事会规模产生了显著的正向的反馈效应,但前期公司绩效并未对当期董事会的独立性产生显著影响。     

The perils of endogeneity and instrumental variables in strategy research: Understanding through simulations

In this paper we use simulations to examine how endogeneity biases the results reported by ordinary least squares (OLS) regression. In addition, we examine how instrumental variable techniques help to alleviate such bias. Our results demonstrate severe bias even at low levels of endogeneity. Our results also illustrate how instrumental variables produce unbiased coefficient estimates, but instrumental variables are associated with extremely low levels of statistical power. Finally, our simulations highlight how stronger instruments improve statistical power and that endogenous instruments can report results that are inferior to those reported by OLS regression. Based on our results, we provide a series of recommendations for scholars dealing with endogeneity. Copyright © 2013 John Wiley & Sons, Ltd.     

Market Making and Trading in Nasdaq Stocks

This paper examines the relations between the number of market makers, trading activity, and price improvement in Nasdaq stocks, using a model motivated by Grossman and Miller (1988). Results indicate a positive relation between the number of market makers and trading frequency, and that competition among market makers reduces effective bid-ask spreads. Results estimated using a simultaneous equations framework support the model predictions of Grossman and Miller. Results also indicate that trading frequency may be more important than trade size in determining the number of market makers.     

The effect of inflation on growth

The paper examines the effect of inflation on growth in transition countries. It presents panel data evidence for 13 transition countries over the 1990–2003 period; it uses a fixed effects panel approach to account for possible bias from correlations among the unobserved effects and the observed country heterogeneity. The results find a strong, robust, negative effect on growth of inflation or its standard deviation, and one that appears to decline in magnitude as the inflation rate increases, as seen for OECD countries. And the results include a role for a normalized money demand in affecting growth, as well as for a convergence variable, a trade variable and a government share variable. Robustness of the baseline single‐equation model is examined by expanding this into a three‐equation simultaneous system of output growth, inflation and money demand that allows for possible simultaneity bias in the baseline model.     

The new Keynesian Phillips curve: endogeneity and misspecification

The wrong or insignificant sign of the forcing variable in the new Keynesian Phillips curve estimations may be a result of the endogeneity of the labour share and misspecification of real marginal cost in the baseline model. We address the misspecification of real marginal cost by formulating a broad measure that features the labour share, output gap and supply shock variables. The endogeneity of the labour share is addressed by using an appropriate lag of the labour share in the Phillips curve. Reduced-form evidence from five developed and five emerging market economies support the empirical validity of the NKPC.     

On Endogeneity Bias: Some General Remarks and Correction of the ROIW Paper by Bourguignon,Ferreira, and Menéndez (2007)

This paper is a short note on the question of correcting for endogeneity bias in a regression. It also points out errors and omissions in the derivation of this bias in Bourguignon, Ferreira, and Menéndez (2007). We show that some assumptions needed for the derivation are not explicit and even under these assumptions, certain simplifications adopted are not valid. We support our points using simulation experiments.     

Trade,scale or social capital? Technological progress in poor and rich countries

Endogenous growth theory suggests scale and trade as the determinants of total factor productivity (TFP) growth. The literature on social capital suggests that the levels of trust and participation in societies may affect cooperation and innovation. While there is evidence of the role of trade and inconclusive evidence on the role of social capital, previous studies have generally omitted two factors, out of the three mentioned, used small sample sizes and emphasized economic growth rather than technological progress. Our study addresses these shortcomings. We find robust evidence of the role of trade in fostering technological progress which is invariant to TFP proxies and independent of the debate on measuring TFP. Moreover, there is no clear role for scale, and a country rate of TFP growth seems to increase the most the more the country trades with dynamic economies that are different from. We uncover a positive effect of social capital, which is more significant in richer countries, suggesting that other characteristics, such as institutional quality, may be complementary to social capital. The paper's results are robust to different specification and estimation methods.     

Southeastern European Trade Analysis: A Role for Endogenous CEFTA-2006?

The objective of this paper is to analyze the impact the Central European Free Trade Agreement of 2006 (CEFTA-2006) has had on trade and provide quantitative comparison with the original CEFTA and with trade liberalization under the EU integration process. The paper belongs to the strand of literature analyzing a free trade agreement in a gravity framework but treating the agreement as being potentially endogenous. The empirical evidence suggests that CEFTA-2006 exerted a positive, significant, and large effect on trade in Southeast Europe. This finding can be largely attributed to the distracted trade flows in the region over the 1990s. The effect of CEFTA-2006 has been estimated to be larger than the effect of the stabilization and association agreements. This counteracts the concern that the EU and the Southeastern European countries formed a "hub-and-spoke" structure in terms of trade.     

货币超发还是输入通胀？——基于MS—VAR模型的视角

通货膨胀及其影响因素之间固有的内生性使得采用单方程分析不可避免会产生偏差。本文运用MS—VAR模型并利用2001年1月～2011年12月月度数据对我国通胀及其影响因素进行了实证分析。结果表明：（1）高通胀水平下货币供应量、石油价格波动以及国内需求和通胀预期对价格水平均会产生正向冲击,而人民币汇率波动对于价格水平的累计冲击响应效应为负;（2）相对而言,货币供应量变动对于通胀水平影响最大。（3）货币供应量上升太快是我国2007年下半年来物价居高不下的主要原因,与汇率变动以及国际石油价格波动等外部冲击因素关系不大。     

Tax policy endogeneity: evidence from R&D tax credits

This paper estimates the causal effect of research and development (R&D) tax incentives on R&D expenditures using new data on U.S. states. Identifying tax variation comes from changes in federal corporate tax laws that heterogeneously and, due to the simultaneity of state and federal corporate taxes, automatically affect state-level tax laws. Instrumental variables regressions indicate that a 1% increase in R&D tax incentives causes a statistically significant 2.8–3.8% increase in R&D. Alternatively, ordinary least squares (OLS) regressions of R&D expenditures on R&D tax incentives, which do not correct for the policy endogeneity of R&D tax incentives, indicate that a 1% increase in R&D tax incentives causes a statistically insignificant 0.4–0.7% increase in R&D. One possible explanation for these results is that tax policies are implemented before an economic downturn.