How Does the Updated Squire Index Measure Legislative Professionalization?

This note revises the author's measure of legislative professionalization, first published 25 years ago. The update corrects a misestimate in some states' session days. It documents the index's academic usefulness and calculates it for 2015.

Key Points

• Revised measure maintains original intent but fixes errors
• Calculation completed for recent year (2015)
• Correction addresses state-specific data accuracy issues