年金制度與世代公平——我國不同世代公務員退休保障的比較

EQUITY ON OLD-AGE BENEFIT SYSTEM: COMPARISONS OF IRR AND MULTIPLIERS ACROSS CIVIL SERVANTS’ GENERATIONS

我國近幾年針對年金改革的討論中，有關年金保障世代差異的問題一直受到高度重視，本文即聚焦於此一議題進行探討。本文針對公務人員退休保障制度，進行實證的分析，比較1971年、1981年、1991年與2001年開始任職的四個不同世代的公務人員之退休保障差異。本研究發現，若從年金獲益倍數（總給付對總繳費的比值）來看，每一個世代的公務員都享有明顯的年金獲益。但比較這四個世代，發現各世代的獲益倍數從11倍到38倍不等，越早開始任職的世代其年金獲益倍數越高。各世代的年金內部報酬率（IRR）亦是越早期的世代越高，從11.0%–23.3%不等。本研究也發現，1995年公務人員退撫新制的改革對於世代公平的影響差異甚巨，新制年資越長、舊制年資越短者，其總繳費越高。整體而言，公務人員，其終身繳費總額有重大的差異，但其終身給付總額差異不大，這與Musgrave（1986）所界定的「恆定調整替代率」（fixed replacement rate）途徑接近。本文並針對行政院年金改革辦公室於2017年初年金國是會議中所提出的各項改革內容進行試算，發現不同的改革項目對不同世代公務人員之退休總給付的影響大不相同。本論文的研究，不僅有助於瞭解在既有制度之下不同世代公務人員的退休保障差異，亦有助於釐清不同的改革途徑對各世代所造成的不同效果。

The recent development of Taiwan Pension Reform has primarily targeted the issues of intergenerational equity. This paper focuses on the empirical analysis of equity within the civil servants, old-age income system, and conducts comparisons for four generations of cohorts whose service years started in1971, 1981, 1991 and 2001 respectively. This study shows that multipliers of benefits to contribution vary across generations, ranging from 11 to 38; the earlier into the system, the higher the multiplier. Internal rates of return, which are derived intherangeof11.0%to 23.3%, display a similar pattern, which is the earlier into the system, the higher the IRR. These findings pinpoint the controversial issues back to the 1995 reform which was biased in favor of those who entered the public sector prior to 1995 and accordingly deteriorated the system’s financial strength. In summary, though the young generation pays more into the system, the benefits received among different cohorts all reflect a high level in terms of the replacement rate and dollar amount. This phenomenon corresponds to the fixed replacement rate theory by Musgrave (1986). In addition to presentation of the current system, this paper also conducts analysis of IRR and multipliers based on the reform draft concluded from the Pension Reform National Symposium of 2016. The degree of impact on the old-age security of civil servants by generation is estimated and presented.