ECONOMIC ANALYSIS OF RISK MANAGEMENT IN THE WORLD ECONOMY

该项目研究了社会保障、贸易冲突、国家安全和再分配政策等风险管理政策。我们审议了公共安全网对宏观经济的影响，以及针对各种风险进行公共和私人调整之间的关系。我们还为包括国防开支、对外援助和减排在内的国际公共产品制定了理论框架。其中，主要成果有以下几点。(1)公共产品的中性定理可以推广到经济增长不能影响实际均衡的情况，如果我们允许减少因增长而造成的污染的活动。(2)如果国际公共利益的作用是减少坏国家的可能性，则它可能成为次要利益。(3)在竞争性经济中，国家安全的稳定水平可能过高，尽管与消费相比，这一水平太低。众所周知，当竞争性的稳态经济走上低效道路时，从长远来看，资本积累可能会过多。这就是收入效应。如果收入效应主导搭便车效应，非合作解决方案的国家安全水平可能大于第一最优水平。社会贴现率越大，处罚比例越小，就越有可能出现这样的悖论情况。(四)增加股本提高实际收入，刺激国家安全需求。为了有更多的国家安全，国家愿意在国家安全上支付更多的支出。国家安全与GDP的比率随着资本积累的增加而增加。我们推导了剥削假说，而不依赖于盟国之间安全支出的公共利益性质。

This project has investigated risk management policies such as social security, trade conflicts, national security, and redistribution policy. We have considered the macroeconomic implications of public safety nets and the relationship between public and private adjustments against various risks. We have also developed theoretical frameworks for international public goods including defense spending, foreign aids, and abatements. Among others the followings are main results. (I) The neutrality theorem of public goods may be extended to the case where economic growth cannot affect the real equilibrium if we allow for abatement activities against pollutions due to growth. (ii) The international public good may become an inferior good if its role is to reduce probabilities of bad states. (iii) The steady-state level of national security may be too much in the competitive economy although it is too little compared with consumption. It is well known that capital accumulation may be too much in the long run when the competitive steady state economy is on the inefficient path. This is the income effect. If the income effect dominates the free-riding effect, the level of national security at the non-cooperative solution could be larger than the first best level. The larger the social discount rate and the smaller the penalty ratio, it is more likely to have such a paradoxical case. (iv) An increase in capital stock raises real income, stimulating the demand for national security. In order to have a larger amount of national security, the country is willing to pay more spending on national security. The national security-GDP ratio increases with capital accumulation. We have derived the exploitation hypothesis without depending on a public good nature of security spending among allies.