信息化对区域创新能力的影响——马太效应存在吗

分析了信息化影响区域创新能力的机理，从信息化资本水平、信息化产业水平和信息化应用水平来测度区域信息化水平，基于2003-2015 年中国29 个省区的面板数据，构建了双固定效应模型，采用LSDV 和GMM 法，实证检验了信息化对区域创新能力的影响以及两者关系的地区差异。结果显示：总体上信息化促进了中国区域创新能力提升，中西部地区信息化对区域创新能力的推动效用明显大于东部地区。这表明，信息化发展并未造成区域创新能力的马太效应。加快推进信息化战略不仅有助于进一步增强中国区域创新能力，而且对于缩小区域创新差距、促进区域协调发展亦有积极意义。     

Effects of cohort size on college premium: Evidence from China's higher education expansion

In this paper, we document the lesser-known heterogeneous trends of college/non-college earnings premium across age groups from 1995 to 2013 in China. Specifically, the college premium in 2013 for the younger group (age 25–34) was about 30 percentage points, similar to the level in 1995, while the college premium in 2013 for the older group (age 45–54) increased to 50 percentage points, nearly double that of 1995. To attribute these divergent trends of the college premium to the changes in the relative size of college workers, we use the model by Card and Lemieux (2001), which incorporates imperfect substitution between similarly educated workers in different age cohorts. Due to the distinctions of these trends in China, our identification is free of the overestimation issue that the existing studies suffer. Our results are similar to those in the U.S., U.K., Canada, and Japan. Holding the age cohort and survey year constant, a one unit increase in log relative size of college workers is associated with about 10 percentage points decrease in college/non-college premium and about 18 percentage points decrease in college/high school premium. We further find that the negative effect is much more substantial among the new entrants (age 25–29) than experienced workers (age 30–54). By this pattern, we demonstrate that the new labor market entrants are more sensitive to their own cohort size and argue that the confounding ability composition effect should not be a serious issue.     

Horse race of weekly idiosyncratic momentum strategies with respect to various risk metrics: Evidence from the Chinese stock market

This paper focuses on the horse race of weekly idiosyncratic momentum (IMOM) with respect to various idiosyncratic risk metrics. Using the A-share individual stocks in the Chinese market from January 1997 to December 2017, we first evaluate the performance of the weekly momentum based on raw returns and idiosyncratic returns, respectively. After that the univariate portfolio analysis is conducted to investigate the return predictability with respect to various idiosyncratic risk metrics. Further, we perform a comparative study on the performance of the IMOM portfolios with respect to various risk metrics. At last, we explore the possible explanations to IMOM as well as risk-based IMOM portfolios. We find that 1) there are prevailing contrarian effect and IMOM effect for the whole sample; 2) the negative relations exist between most of the idiosyncratic risk metrics and the cross-sectional stock returns, and better performance is linked to idiosyncratic volatility (IVol) and maximum drawdowns (IMDs); 3) additionally, the IVol-based and IMD-based IMOM portfolios exhibit better explanatory power to the IMOM portfolios with respect to other risk metrics; 4) finally, higher profitability of IMOM as well as IVol-based and IMD-based IMOM portfolios is found to be related to upside market states, high levels of liquidity and high levels of investor sentiment.     

The valuation effect of stock dividends or splits: Evidence from a catering perspective

We hypothesize that managers use stock dividends or splits to cater to gambling investors who are willing to pay a premium for stocks with lottery-like features. Using proprietary account-level trading records, we find that retail investors, particularly those with a strong gambling preference, become strong net buyers following the announcement of stock dividends, while professional investors unload their holdings. Moreover, we find that positive market reactions to stock dividends is positively associated with increases in gambling investors.     

Relevance of the disposition effect on the options market: New evidence

A moneyness‐based propensity to sell (MPS) measure, at the aggregate level, determines the propensity of option holders to exercise their winning relative to losing positions. Using data on individual stock and S&P 500 Index options, we find that the MPS measure has significant predictive power over the cross section of delta‐hedged option returns. We test the disposition effect in the options market based on a long–short strategy that exploits price distortions induced by the disposition bias. More pronounced evidence of the disposition bias is found for individual at‐the‐money call options than put options where the significance of abnormal returns remains robust across different subsamples even after we control for the portfolio option greeks and market‐based risk factors. The profitability of the long–short strategy is related to limit‐to‐arbitrage proxies suggesting that behavioral explanations help explain the positive relation between the MPS measure and delta‐hedged option returns.     

市场分割与区域创新溢出

通过估算2001—2016年29个省区市的市场分割指数,结合区域创新指数和区域经济特征数据,采用空间计量方法研究了市场分割对地区创新绩效的直接影响与间接影响。研究结果表明,整体上,区域技术创新存在显著的空间正相关关系,省份内市场分割的直接效应、省份间市场分割的间接效应以及两者的总效应对区域创新均表现出显著的抑制作用,并且本地市场分割对创新指数提升的抑制作用大于省份间市场分割的间接作用。     

社会资本视角下农村基础设施管护效果影响因素分析——基于甘肃省9个市县的实证研究

以甘肃省9个县市的调查数据为基础,将社会资本划分为社会参与、社会规范、互惠网络三个维度,运用结构方程模型,来探讨三个维度对农村基础设施管护效果的影响。结果表明:(1)社会规范对农村基础设施管护效果显正向影响。(2)互惠网络对农村基础设施管护效果显负向影响。(3)社会参与对农村基础设施管护效果的直接影响不显著,但通过社会规范及互惠网络间接产生影响。(4)就总效应而言,社会规范对农村基础设施管护效果的影响要大于社会参与及互惠网络产生的影响。     

温州市区及瑞安市区校园直饮水净化系统处理前后水质分析及风险监测

经对温州地区40所中小学校园自来水及净化后的水质进行检测分析,该地区自来水基本符合《生活饮用水卫生标准》(GB 5749—2006)要求,但50%以上学校净水器净化后的水中菌落总数反而超标,净水器微生物产生了二次污染。另外,金属元素、无机非金属、感光性状及物理性状等项目净水器影响不是很大。     

增信服务还是腐蚀效应:论金融科技等新兴产业发展过程中的风险信号

提出行业性风险暴发的"腐蚀效应"理论,即存在着一种特殊的行业风险暴发过程:行业中各个企业的倒闭是沿着企业的资质链从低到高的顺序发生的.该过程的存在得到了数据回归证实.对于科技金融等新兴行业,警惕和积极防范腐蚀效应,对防范行业性风险具有重要意义.对于客户信任高度依赖的新兴行业,如金融科技等,最容易出现腐蚀效应.因此,在一度高速膨胀的网络贷款领域出现腐蚀效应具有一定必然性."腐蚀效应"的存在也否定了当前把网络贷款行业大面积爆雷的原因归咎于其开展"增信服务"的普遍观点,真正引发风险的原因是网络贷款行业中的企业资质参差不齐和无序竞争造成的无谓成本的大幅增加.从政府对行业的管理视角来看,在促进行业发展时不忘记防范风险十分重要.这在实质上是对制度-制度接口的设计问题.因此应当以制度设计理论来指导防范风险政策的制定,才能取得更好的效果.     

Dynamic time series momentum of cryptocurrencies

This paper examines the momentum effect for twenty cryptocurrencies compared to the US stock market. For this purpose, we implement a dynamic modeling approach to define and test momentum periods that follow a formation period for interday and various intraday price levels. We find evidence that large proportions of the asset classes’ formation periods are followed by momentum periods, strongly supporting the momentum effect. In particular cryptocurrencies have significantly larger and longer momentum periods in all frequencies which we attribute to the lower derivability of their intrinsic value leading to a higher degree of noise traders in the market. A momentum trading strategy based on the identical approach outperforms a buy-hold strategy for both asset classes, while only cryptocurrencies have higher risk-adjusted returns and lower downside risks than a passive investment. We also find critical price levels during structural elements of the momentum period where the volatility shortly but intensively increases and consequently initiates a price impulse in the direction of the momentum.