ECONOMIC ANALYSIS OF RISK MANAGEMENT IN THE WORLD ECONOMY

该项目调查了风险管理政策，如社会保障、贸易冲突、国家安全和再分配政策。我们考虑了公共安全网的宏观经济影响，以及针对各种风险的公共和私人调整之间的关系。我们还开发了国际公共产品的理论框架，包括国防开支、对外援助和减排。其中，以下是主要结果。(1)公共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，如果我们考虑到对增长造成的污染的减排活动。（ii）如果国际公共产品的作用是减少出现坏国家的可能性，它就可能成为次等产品。（三）国家安全的稳态水平在竞争经济中可能过高，但与消费相比却过低。众所周知，当竞争的稳态经济走上无效率的道路时，从长期来看，资本积累可能过多。这就是收入效应。如果收入效应大于搭便车效应，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。社会贴现率越大，惩罚比率越小，就越有可能出现这种矛盾情况。资本存量的增加提高了实际收入，刺激了对国家安全的需求。为了拥有更大的国家安全，国家愿意在国家安全上支付更多的开支。国民安全与gdp之比随着资本积累而增加。我们得出了剥削假设，而没有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.