探析中小样本负案例选择——以石油武器化发生为例OACHSSCD

Case selection is a a critical step in the research design of the social sciences.The seminal writing of James Mahoney and Gary Gertz systematically elaborated on"the Possibility Principle"of negative case selection with event/phenomenon onset as the dependent variable.The principle consists of the"Rule of Exclusion"and the"Rule of inclusion".Despite their substantial contributions,the writing entails at least three significant limitations.First,their methods and illustrative examples seem designed for small-N analysis,leaving the applicability of the two rules to medium-N research unexplored.Second,even for small-N studies,they did not exhaust the procedures and methods of negative case selection.Third,their implementation of the"Rule of Exclusion"was implicit.In response to the above weaknesses,this methodological essay applies and develops"the Possibility Principle",proposing a general path for selecting negative cases in small-N and medium-N studies in which the dependent variable is dichotomous.Specifically,we takes the onset of oil weaponization as an example,applying the"Rule of Exclusion".Based on the values of the main independent variables and the dependent variable,our approach spells out three types of structural constraints,theoretical elimination,and empirical supplemental conditions,and use them to eliminate irrelevant cases stepwise.Second,we adhere to the"Rule of inclusion"and retain cases in which at least one independent variable boasts of a positive correlation with the dependent variable.Finally,we adopt Gerring's typological-framework for"diverse case selection"and run random samplings bases on it,then complete negative case selection.