본 논문은 우리나라의 인구구조 변화가 초래하게 될 거시경제적 결과를 연구의 대상으로 하고 있다. 이를 위해 Diamond(1965)에 의해 개발된 고전적인 세대교차모형Overlapping Generations Model을
변형하여 이용하였다. 즉 본 연구에서는 세대교차모형을 변형하여 Diamond의 경우와 달리 생애의 세 기간을 세분화하여 교육기간 과 평균수명의 개념을 추가하였다. 이와 같은 모형을 이용하여 본 연구는 인구증가율, 평균수명, 교육년수 그리고 기술진보율이 변 화할 때 나타나는 거시경제적 효과를 분석하여 보았다. 분석결과 가운데 특히 주목할 것은 연금지급률을 일정하게 유지하는 제도 는 유지불가능하며 특히 고령화가 빠르게 진행될 때 재정에 미치 는 부담은 우리가 대처할 수 없을 정도로 클 수 있음을 보여주고 있다. 따라서 지금의 인구구조의 변화가 우리나라의 저축률, 이자 율, 연금제도 등 거시경제에 미치는 효과를 완화하기 위해서는 먼 저 연금제도가 시급하게 개선되어야 하며 그와 함께 인구정책과 교육정책 등이 함께 종합적으로 개혁되어야만 한다. 나아가 지금 까지 기금으로 축적되어 있는 연금의 수익성을 높이는 방법에 대 해서도 연구되어야 한다. 그러나 연금기금의 금융투자에 따른 위 험성도 동시에 고려되어야 하며 그 연금기금의 본래 목적 이외의 목적이 우선하는 투자의 경우에는 머지않은 장래에 더욱 큰 문제 를 야기할 수 있음을 유념할 필요가 있다.
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Abst rac t
Macroeconomic Effects of Demographic Changes in Korea
Cho, Jang-Ok*
This paper looks at the effects of changes in population structure. In the paper, the two period overlapping generations model of the sort developed by Diamond (1965) and d'Autume (2003) is extended to 3-period OG model and modified to distinguish the effects of aging population from changes in the population growth rate. Pension system is assumed to be of pay-as-you-go.
In addition, education is also introduced to see the macroeconomic effects of changes in the length of education period. The model is calibrated to the Korean economy and simulated to get the following results. In a pay-as-you-go system of pension, the replacement rate has to be linked to many factors like population growth rate, retirement age, and the rate of wage increase etc.
Hence if the pay-as-you-go system is to be sustainable in the
* Economics Department, Hong Kong University of Science and Technology, and Economics Department, Sogang University
long run, the replacement rate should not be fixed but contingent to the changes in the underlying variables.
In Korean case, if the replacement rate is fixed at the current level, the increase in the budget deficit due to pension payment can be as much as 0.176% of GDP in the case that the rate of population growth decreases to 0% per annum and as much as 0.99% in the case that the population growth rate decreases to 0.3% per annum. We can have the result as drastic as above in the case of aging population. If the life expectancy increases from 73 years to 78 years, the budget deficit has to increase by 0.65% of GDP to keep the current replacement rate. In this case, the increase in the life expectancy makes individual want to work more in the market by 2 years and 6 months. Increase in human capital due to longer education lowers the tax burden of pension payment. If the education increases from 18 to 21 years on average, budget deficit decreases by 0.26% of GDP.
When any demographic changes occur, most of the macroeconomic adjustment takes place in the earlier stage of the transition dynamics, which means that the policy makers have to respond to the changes rather promptly. With the retirement age fixed, we can arrive at almost the same results. However, the adjustment channel after any demographic changes is mainly saving and interest rate. The most conspicuous policy implications out of these exercises are the followings. First, the replacement rate in a pay-as-you-go system has to be linked to the underlying factors. If a pension reform aims at changing replacement rate to a lower fixed level, subsequent reforms have to follow inevitably.
Second, since any demographic changes directly affect macroeconomic performances, macroeconomic policies have to take into account the consequences of those demographic changes.
제3장 고령화가 개별 가구의 소비, 저축 및 자산규모에 미치는 효과분석
-한국 가구의 횡단면 시계열을 이용한 세대효과 분석
남 주 하
(서강대학교 경제학과 교수) 이 수 희
(한국경제연구원 선임연구위원) 김 상 봉