1 Summary of the Paper

（ひとことメモ）

  • 保険マーケットにおける諸問題のうち、InertiaとAdverse Selectionの関係に注目した論文。
  • いずれも保険マーケットの効率性を損なう問題として捉えられているが、両者には「Inertiaを減らして消費者が良い選択をできるようにするほどAdverse Selectionを助長する」という関係がある。
  • そのため、（何らかの）NudgeによりInertiaを減らすことで、かえって経済厚生を損なう可能性がある。

1.1 Motivation

  • Investigate consumer inertia in health insurance markets.
  • Potential concern of insurance markets:
    • Adverse Selection
    • Moral Hazard (hardly discussed in this paper)
    • Inertia: consumers are reluctant to make active choices
  • Focus on the relationship between adverse selection and inertia.
  • To do so, a choice model is developed and estimated, and using these estimates counterfactual simulation is conducted to study the impact of policies that nudge consumer toward better decisions by reducing inertia.
  • The improved choices substantially exacerbate adverse selection, leading to an overall reduction in welfare (“When Nudging Hurts”).

1.3 Contribution

  • Explicitly quantify the value of inertia and other micro-foundations
  • Use those estimates to study the interaction between inertia and adverse selection