Question

what did Harding, Coolidge, and Hoover have in common, regarding their economic and political philosophies

Answer 1

All 3 believed in a laissez-faire economic policy.
This means that the government does not interfere in the national economy as a whole (rather than just businesses) in any MAJOR way - rather than not at all - unless absolutely necessary,and then only to give it a nudge back in the right direction. :) hope this helped!!!