「回归(regression)」不仅是众多统计方法的本质,更是我们理解这个复杂世界的重要思想工具(Blog: Common statistical tests are linear models)。世界很复杂,但在科学的视角下,很多现象或行为都可以被简化为回归模型——现象或行为本身是“观测项”,我们还会用一系列其他变量来解释或预测这个观测项,其中,一部分是我们能够...
aTable 3 reports three different estimates of the parameters in specification (1): the pooled ordinary least squares (OLS), the between, and the fixed-effects (within) models. Though each model is based on different assumptions, all three produce an estimate of that is positive and high...
aThe fixed-effects estimator is perhaps more preferable, however, as it does not rely on the assumption that i is uncorrelated with the other explanatory variables. Identification for this model comes from only variation year-to-year within companies. The advantage of having a [translate] ...
acharacteristics of time series and cross sections may have firm specific effects, period specific effects, or both. There are three types[translate] aeffect nor a period specific effect, we could pool all of the data and run an OL S regression model [72] . Although there are of ten[tran...
aThis model includes the factors (fixed effects) for treatment, randomization strata (region, disease severity), visit, treatment by visit interaction, and relevant baseline value. Within the framework of MMRM, the treatment difference will be tested at the prespecified primary time point, week 16...
aeffect nor a period specific effect, we could pool all of the data and run an OL S regression model [72] . Although there are of ten[translate] aperiods, whereas the random effect model explores differences in error variances. The fixed effect model, also known as least[translate] ...