The Impact of Merger-Related Regulations Using Exact Distributions of Test Statistics
推导了Schipper和Thompson（1983）模型中检验统计量的有限样本精确分布，并利用该分布重新检验了威廉姆斯修正案对股东财富的平均影响，确认其负面且统计显著。
In Schipper and Thompson [1983] (henceforth ST), we estimated a pooled cross-section, time-series model of the return-generating process for the common stock in a sample of related firms. Some of the test statistics reported, based on linear constraints across estimated coefficients, are quadratic forms in the sample covariance matrix. Under the structure and assumptions of the model, these test statistics have asymptotic chi-squared distributions (as the number of time-series observations goes to infinity). In that paper, we did not discuss the exact distributions of these test statistics. In this paper, we show that under the assumption of normality of residuals, the test statistics reported in ST involving asymptotic chisquared distributions have convenient finite sample distributions which can be used to test some of the hypotheses examined there.1 In doing so we reaffirm that the average impact on shareholder wealth of the Williams Amendments was negative and statistically significant for the