More risk-averse voters prefer less insulated systems so reforms stay blockable.

Evidence

Proof: See Appendix. Thus, more risk aversion leads to lower insulation: in choosing insulation, ex ante the voter takes into account the risk of falling below 0 ex post. Thus, more risk aversion leads to choosing a system were ex post policy reforms can be more easily blocked. — Philippe Aghion, Alberto Alesina, and Francesco Trebbi, Endogenous Political Institutions, 102