Policy Uncertainty and the Cost of Delaying Reform: A case of aging Japan

高齢化が進行する中、数十年前に確立された賦課方式の年金制度を維持するには、給付額の引き下げあるいは大規模な増税が避けられない。しかしながら多くの場合において改革の時期やその内容について不確実性が存在する。本稿では高齢化が進む経済において年金改革に関する政策の不確実性を明示的にモデルに組み込み、政策の不確実性および改革の先送りによる経済的および厚生的費用を計量分析する。急速な高齢化と深刻な財政問題に直面する日本のケースを用い、政策の不確実性は経済、厚生両面に著しい影響を及ぼすことを明らかにする。改革の先送り、改革規模の縮小は現在の中高齢者にとっては好ましいがそれは同時に若者および将来世代の負担増と厚生の悪化を意味し、大規模な世代間のトレードオフが生じることを示す。

In an economy with aging demographics and a generous pay-as-you-go social security system established decades ago, reform to reduce benefits is inevitable unless there is a major increase in taxes. Often times, however, there is uncertainty about the timing and structure of reform. This paper explicitly models policy uncertainty associated with a social security system in an aging economy and quantifies economic and welfare effects of uncertainty as well as costs of delaying reform. Using the case of Japan, which faces the severest demographic and fiscal challenges, we show that uncertainty can significantly affect economic activities and welfare. Delaying reform or reducing its scope involves a sizeable welfare tradeoff across generations, in which middle to old-aged individuals gain the most at the cost of young and future generations.

Published: Kitao, Sagiri, 2018. "Policy uncertainty and cost of delaying reform: The case of aging Japan," Review of Economic Dynamics, Vol. 27, pp. 81-100
https://www.sciencedirect.com/science/article/pii/S1094202517300947