Indicator lists can never be complete and should be redundant.

Evidence

Indicators are ideally redundant. The possible list of indicators has no end: there is no need to have a complete list of indicators. These two facts about concept construction dramatically illustrate that how to think about the secondary level differs from the data–indicator level. — Gary Goertz, Social Science Concepts and Measurement, 151

Categorization

• SEED: Angle: ‘Completeness and Redundancy Stop Meaning the Same Thing One Level Down’ — why the two design virtues invert between levels.
• XREF: Directly parallels the Milgrom point that full information about all traders is costly and unnecessary — informational sufficiency beats exhaustive information.