The Effect of Certain Research Design Choices on the Assessment of the Market's Reaction to LIFO Changes: A Methodological Study
探讨实证研究中控制组设计如何影响市场对LIFO会计变更反应的评估，指出自我选择偏差可能混淆结果，并讨论匹配方法的应用。
A major objective of the research design of an empirical study is the elimination of as many rival hypotheses as possible. One strategy frequently used for this purpose is to employ control groups as standards of comparison (such as used by Dyckman and Smith [1979] and Collins and Dent [1979] in their assessments of the exposure draft of FASB Standard 19). Ideally, any observed difference between an experimental group and a control group should be due to the experimental condition. In true experiments, this is more likely to be achieved through a random selection of subjects, followed by their random assignment to the experimental and control conditions. However, market-based research is ex post; the researcher does not exercise control over the independent variable(s) nor over the assignment of firms to the experimental or control group. The self-selection of firms into their respective groups introduces the possibility that self-selection biases may confound the results. Firms may differ on characteristics other than the independent variable(s), and these differences may induce variations in the dependent variable. One approach used to reduce the likelihood of self-selection bias is to match the experimental and control group on variables that, on an a priori basis, are believed to influence the dependent variable.1 Harrison [1977], for