Widespread weakest-link use converted strict nonsubstitutability into an untested working assumption.

Evidence

The strict nonsubstitutability of democratic constraints is now a common working assumption among democratic peace researchers due to the widespread use of weakest-link measures. But this is certainly not the only plausible assumption one could adopt. For example, we could postulate partial substitutability in the sense that one state’s highly democratic norms or institutions actually entail some limited constraining effect on other states irrespective of their form of governance. — Gary Goertz, Social Science Concepts, 879

Categorization

• QUESTION: Is there empirical work testing partial substitutability—i.e., whether democratic states moderate non-democratic partners’ behavior—rather than assuming it away?
• SEED: Article angle: ‘How a measurement convention hardened into a fact’—tracing weakest-link’s migration from a modeling choice to undisputed background knowledge across an entire research program.
• XREF: Echoes the earlier chapter’s point that weakest-link logic was treated as accepted background knowledge exempt from scrutiny.