Recent studies have found that resource-rich low-income countries are better off investing their resource revenues domestically rather than saving them abroad in a sovereign wealth fund (SWF). This paper finds an optimal rule-based policy of accumulating public capital and its associated public investment path in a perfect foresight general equilibrium model. The model has several specific features different from the existing frameworks: the policy rule for public capital is introduced. Public investment is inefficient and has its absorptive capacity constraint costs. External savings clear the government budget. There is a variable share of resource revenues to accumulate the SWF, and the natural resource sector is assumed to be capital-intensive with its foreign direct investment shock. Based on calibration for African countries, the study finds that the front-loaded public investment path is optimal given an initial one-period resource windfall, public investment inefficiency and absorptive capacity constraints in the economies. This result also holds under less productive public capital and more patient households, while a scenario of no resource windfall produces the welfare loss due to a steady increase in consumption tax to finance public investment.

中文翻译：

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资源丰富的低收入国家的最佳公共投资

最近的研究发现，资源丰富的低收入国家最好将其资源收入投资于国内，而不是将其存入主权财富基金（SWF）。本文在一个完美的前瞻性一般均衡模型中找到了一个最优的基于规则的公共资本积累政策及其相关的公共投资路径。该模型有几个不同于现有框架的具体特点：引入了公共资本的政策规则。公共投资效率低下，并有其吸收能力约束成本。外部储蓄清除了政府预算。积累 SWF 的资源收入份额是可变的，自然资源部门被认为是资本密集型的​​，受到外国直接投资的冲击。基于对非洲国家的校准，研究发现，考虑到最初的一期资源意外收获、公共投资效率低下和经济体的吸收能力限制，前期公共投资路径是最优的。这一结果在生产力较低的公共资本和更多耐心家庭的情况下也成立，而在没有资源意外收获的情况下，由于消费税稳步增加以资助公共投资，因此会产生福利损失。