The study was not performed in a randomized controlled manner in comparison with an appropriate control group or with an alternate treatment option like microfracturing.
Matching for standard parameters and severity of illness identified an appropriate control group.
The identification of any causal effect deriving from the Great Recession is complicated because it is extremely hard to find an appropriate control group.
Moreover, the identification of any causal effect of the Great Recession is complicated by the difficulty in finding an appropriate control group.
What is more, studies often tend to focus exclusively on children in transnational care, without considering an appropriate control group of children in non-migrant households.
We employ propensity score matching to select an appropriate control group of untreated firms on the basis of the probability that they participate to U I partnerships.
Prior studies on donor egg in vitro fertilization (DE-IVF) outcomes have been limited by the lack of an appropriate control group.
Study designs using related controls as a more appropriate control group for evaluating G×E interactions have been proposed but often assume unrealistic numbers of available relative controls.
In order to identify this term I assume that all differences between high-growth firms and the appropriate control group can be captured by a vector of observables including the pre-shock size and productivity of a firm.
In contrast, a well-designed experiment has internal validity because all but one of the variables have been controlled through the use of an appropriate control group, but does not have external validity as a result of that control.
In contrast, a well-designed experiment has internal validity because all but one of the variables have been controlled through the use of an appropriate control group, but does not have as a result of that control.
