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。我们考虑了公共安全网的宏观经济影响，以及公共和私营部门针对各种风险进行的调整之间的关系。我们还开发了国际公共产品的理论框架，包括国防开支，对外援助，和援助。主要结果如下。(I)公共物品的中性定理可以推广到经济增长不能影响真实的均衡的情况，如果我们允许由于增长而产生的对污染的减排活动。(ii)如果国际公益的作用是减少坏国家出现的可能性，那么它就可能成为次善。(iii)在竞争经济中，国家安全的稳态水平可能太高，尽管与消费相比它太低。众所周知，当竞争性稳态经济处于非效率路径时，资本积累在长期内可能过多，这就是收入效应。如果收入效应超过搭便车效应，则非合作解决方案下的国家安全水平可能大于第一最佳水平。社会折现率越大，处罚比例越小，就越容易出现这样的悖论情况。(iv)资本存量的增加提高了真实的收入，刺激了对国家安全的需求。为了国家安全有更大的数额，国家愿意在国家安全上付出更多的开支。国家安全-GDP比率随着资本积累而增加。我们推导出了剥削假设，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.