Concept extension tracks how many defining dimensions a rule requires

Evidence

In his analysis of welfare state formation Hicks considered that a welfare state had formed in 1920 if it provided at least three of four classic services of welfare states: (1) old age pensions, (2) workers accident compensation, (3) health care, and (4) unemployment insurance. To examine how the ladder of generality can work in the opposite direction we can contrast two family resemblance rules: (1) a welfare state exists if it has at least one of two services or (2) a welfare state exists if it has at least two of four services. In short, I use the m-of-n rule of one-half: in one case it is “at least one of two” and in the second it is “at least two of four.” — Gary Goertz, Social Science Concepts, 501

Categorization

• DEFINE: The m-of-n family resemblance rule is defined concretely as a one-half threshold applied to two versus four service dimensions.
• XREF: Connects to the earlier chapters of this book on necessary-and-sufficient versus family resemblance structures of concepts.