透明度提高改善了国债市场的质量吗?

2003年12月8日,上海证券交易所提供的报价实时行情由三档价格增加到五档价格,电子委托单薄向交易者提供的信息增多标志着市场透明度的提高。本文对在上海证券交易所交易的16只国债进行了实证研究,发现透明度增加之后,信息和价格有效性提高了,但是市场流动性变差了,价格波动性上升了,投资者的交易成本也上升了。交易者为了规避更高的交易成本,首先,选择了拆分委托单,隐藏真实的流动性需求,减少信息暴露;而委托单拆分的结果,导致交易执行时间变长;另外,交易者还倾向于将委托单的提交时间分散化,减少了大额委托单比例高的收盘期的大额委托单提交量,而相应的增加了大额委托单比例低的开盘期的大额委托单提交量。

土地调整与农地租赁市场:基于数量和质量的双重视角

土地调整对农地租赁市场发育的影响是本文所关注的问题。以往的研究大多只强调农地租赁市场的交易数量,而忽略了市场发育的质量。本文从农地租赁市场交易数量和交易质量的双重视角出发,在建立市场交易模型的基础上,推导出如下理论命题:(1)土地调整会增加非农就业与租赁市场上的土地供给,在供给弹性小于需求弹性的远郊地区,这会增加农地租赁市场的交易数量。(2)土地调整对农地租赁市场的交易质量有着负面的影响,它使得农户间租赁签订契约的可能性下降,租赁期限缩短,并进而降低农户对土地的投资。本文利用2000年苏、浙、鲁53个村、2001年苏、浙、鲁30个村和2009年陕、浙36个村的2398户农户的第一手调查数据对上述命题进行了检验。

Earnings Restatements and Insider Trading： An Empirical Analysis

This study examines the relationship between earnings quality and insider trading. Using downward earnings restatement firms to identify low-quality earnings, we find that insiders outsell non-earnings restatement firms of their holdings over the period from two years before to one year after the beginning of the restatement period. In addition, the amounts of restatement are positively associated with the excess insider selling. We also provide evidence that excess insider selling predicts excessive earnings manipulations that eventually lead to GAAP （Generally Accepted Accounting Principles） violation. Some researchers argued that insider trading can be an efficient way of transferring insider information to the capital markets. Our evidence of intensive insider selling in the context of earnings restatements implies that insiders disregard their fiduciary duties to the shareholders during the periods of deteriorating financial performance.