Anomalies: The January Effect
介绍经济学中的异常现象，即与主流理性预期范式不一致的实证结果，并以一月效应为例，指出股票价格（尤其是小公司和近期下跌的股票）在1月倾向于上涨，且风险溢价主要集中在该月。
This feature will report successful searches for disconfirming evidence -- economic anomalies. As suggested by Thomas Kuhn, an economic anomaly is a result inconsistent with the present economics paradigm. Economics is distinguished from other social sciences by the belief that most (all?) behavior can be explained by assuming that agents have stable, well-defined preferences and make rational choices consistent with those preferences in markets that (eventually) clear. An empirical result is anomalous if it is difficult to “rationalize,” or if implausible assumptions are necessary to explain it within the paradigm. The first anomaly we will discuss is the “January effect.” Stock prices tend to rise in January, particularly the prices of small firms and firms whose stock price has declined substantially over the past few years. Also, risky stocks earn most of their risk premiums in January.