Case Studies and Theory Development in the Social Sciences - Alexander L. George [99]
If the consistency identified appears to be causal and not spurious, the investigator may attempt to assess whether the independent variable is a necessary condition for the outcome in question. This question, of course, may be difficult to resolve. Efforts to do so will require the investigator to move beyond within-case analysis. Ideally, one would try to find other cases in which the same type of outcome occurred in the absence of that independent variable. If such a case(s) were discovered, then the independent variable could not be regarded as a necessary condition.387
When one or more comparable cases are not available, then the investigator can resort to analytical imagination to think of hypothetical cases that might help to judge whether the same type of outcome might occur in the absence of that independent variable. In other words, the investigator resorts to counterfactual analysis and mental experiments in an effort to create a controlled comparison.388 Disciplined use of analytical imagination will at least provide a safeguard against the temptation to move too quickly and confidently from the earlier judgment that consistency was not spurious to the further inference that the independent variable is a necessary condition for the occurrence of that type of outcome.389 If the grounds for regarding the independent variable as a necessary condition are shaky or dubious, as is often likely to be the case, then it is advisable to claim no more than that the type of independent variable in question appears to favor—make more likely—the occurrence of a certain type of outcome. In other words, the independent variable is a contributing cause, though neither necessary nor sufficient.
Analysts should also address the question, “Is the independent variable that is causally related to this particular outcome of the case also consistent with other possible outcomes?” In the analysis of a single case, history provides only one outcome of the dependent variable. Accordingly, it is easy to overlook the possibility that other outcomes, had they occurred, might also have been consistent with the value of that independent variable. Once again, if the investigator cannot locate cases in which the independent variable with the same value was accompanied by diverse outcomes, he or she can resort to disciplined imagination to assess this possibility. To do so, the investigator should immerse himself or herself in the rich details of the historical case being examined; this may enable him or her to envisage with greater confidence that the outcome might well have gone in different directions even with the independent variable held constant, had variation occurred in other operative independent variables. If there is reason to believe this might have been so, the investigator must assign weaker general predictive and explanatory power to the independent variable in question. It should be noted that broadening the assessment of the causal status of the independent variable (or theory) in question requires that the investigator take into account that other independent variables in the case may have played a role in producing that outcome.
Still another question can be asked: “Is it possible to conceive of any outcomes of the historical case that would not have been consistent with the independent variable?” Investigators should attempt to identify outcomes that would be inconsistent with the independent variable and associated conditions because this highlights the need to construct falsifiable theories. By immersing oneself in the historical case, the investigator might envisage a number of other possible outcomes interestingly different from the historical outcome that would also have been consistent with the implications of the independent variable. If so, then the independent variable (of the deductive or empirical theory in question) may be part of the explanation, but its ability to discriminate among alternative outcomes and its predictive power are much weakened.390 On the other hand, if the investigator cannot