When Do We Start? Pension reform in aging Japan

日本では前例のないスピードと規模で高齢化が進んでいる。出生率は過去40年にわたり人口維持に必要な再生産率を大きく下回り、平均余命は1950年代以来約30年上昇している。2004年の年金改革による支給額削減は機能しておらず年金財政再建の目処は立たない。65歳という基礎年金の支給開始年齢は制度発足当初と変わらず支給年齢引き上げを進める他の先進国と比べて最も低い水準となる。本論文においては30年かけて公的年金の所得代替率を20%減らし支給開始年齢を3年引き上げる年金改革を想定し、2020、2030、2040の各年において改革が開始されるケースを分析する。改革の先送りは経済活動を停滞させ、20年の遅れにより総生産は4%低下、総消費の8%に上る財政負担の上昇が生じ、将来世代の厚生は生涯消費の3%相当分悪化する。

Japan is going through rapid and significant demographic aging. Fertility rates have been below replacement level for four decades, and life expectancy has increased by 30 years since the 1950s. The pension reform of 2004 is expected to reduce the replacement rate, but there is much uncertainty as to when and whether the adjustment will be complete. The normal retirement age of 65 will be the lowest among major developed countries. This paper simulates pension reform to reduce the replacement rate by 20% and raise the retirement age by three years gradually over a 30-year period. We consider three scenarios that differ in timing to initiate reform and let the consolidation start in 2020, 2030, and 2040, respectively. A delay would suppress economic activities, lowering output by up to 4% and raising the tax burden by more than eight percentage points of total consumption. Delaying reform also implies a major tradeoff across generations and deteriorates the welfare of future generations by up to 3% in consumption equivalence.

Published: Kitao, Sagiri, 2017. "When do we start? Pension reform in ageing Japan," The Japanese Economic Review Vol. 68(1), pp. 26-47
http://onlinelibrary.wiley.com/doi/10.1111/jere.12135/full