To Omit or to Include? Integrating the Frugal and Prolific Perspectives on Control Variable Use
整合了管理研究中关于控制变量使用的节俭与丰裕两种对立视角，通过蒙特卡洛模拟检验其建议，发现省略无效控制变量和避免代理变量可能有害，而包含内生控制变量则有害，建议基于内生性和因果图来选择控制变量。
Over the recent years, two perspectives on control variable use have emerged in management research: the first originates largely from within the management discipline and argues to remain frugal, to use control variables as sparsely as possible. The second is rooted in econometrics textbooks and argues to be prolific, to be generous in control variable inclusion to not risk omitted variable bias, and because including irrelevant exogenous variables has little consequences for regression results. We present two reviews showing that the frugal perspective is becoming increasingly popular in research practice, while the prolific perspective has received little explicit attention. We summarize both perspectives’ key arguments and test their specific recommendations in three Monte Carlo simulations. Our results challenge the two recommendations of the frugal perspective of “omitting impotent controls” and “avoiding proxies” but show the detrimental effects of including endogenous controls (bad controls). We recommend considering the control variable selection problem from the perspective of endogeneity and selecting controls based on theory using causal graphs instead of focusing on the many or few questions.