کاهش ارزش پول و سرمایه گذاری در یک مدل بهینه سازی از اقتصاد باز کوچک

We analyze the impact of devaluation on sectoral investment, aggregate investment, and real output in a fully articulated, optimizing model of a small open economy where installed capital is sector-specific and new capital goods are constructed by combining nontraded inputs with non-competitive imported machines. Investment falls when the intertemporal elasticity of substitution and the share of domestically produced capital goods are not implausibly large. This result is robust to a wide range of parameter values and to the possibility that saving–investment decisions are made by heterogeneous agents instead of a representative agent.

Two findings of this paper are relevant to the debate on adjustment policy in LDCs. First, and most obviously, there is a very strong presumption that devaluation reduces aggregate investment. Investment falls when the intertemporal elasticity of substitution and the share of domestically produced capital goods are not implausibly large. This result is robust to the degree of demand-side openness, the degree of labor mobility, the flexibility of technology, the export share of primary products, sectoral factor-intensity rankings, and the possibility that saving–investment decisions are made by heterogeneous agents instead of a representative agent. The extent to which the temporary reduction in investment represents a problem, however, is open to dispute. In our model, investment recovers quickly from any sharp initial decline; consequently, the aggregate capital stock and real output never drop very far below their pre-devaluation levels during the adjustment process. This may be judged a modest price to pay for a significant improvement in the balance of payments. The other finding which merits emphasis is that devaluation is most contractionary in poorer LDCs. Investment falls most and the adjustment problems are greatest (especially in the high-wage industrial sector) when the share of domestically produced capital goods and the intertemporal elasticity of substitution are small. Moreover, a devaluation-assisted cut in the real wage increases the equilibrium capital stock when the share of domestically produced capital goods is around its ‘average’ value (0.5) but provokes significant capital decumulation when the share is small. All of this adds up to a consistent picture of devaluation working least well in the least developed LDCs that are highly dependent on imported capital goods (and where τ is probably smaller than in other countries). 33