Trade, Growth and Increasing Returns to Infrastructure: The Role of the Sophisticated Monopolist

Ashok S Guha, Brishti Guha
Paper No. 03-2008

We model an economy with two final goods, manufactures produced under IRS and food. The scale economies in manufacturing are external (therefore compatible with perfect competition) and traceable to internal economies in the provision of an infrastructural service (the third sector of the economy). We examine the equilibria of this economy under both autarky and free trade.
We thus revisit a theme with a voluminous literature, beginning with R. C. O. Matthews(1950) vintage classic and including, among others, Panagariya (1991), Krugman (1991), and Venables (1996). Much of this as well as our own work concerns multiple equilibria: it overlaps the development literature on poverty traps from Rosenstein Rodan (1943) to Murphy, Schleifer and Vishny (1989). We differ from this body of work in a major, and some minor, respects. We trace the source of increasing returns to infrastructure, and our focus is on the role of the infrastructure providers beliefs in determining the equilibrium and the fate of the economy.
Internal economies in infrastructure provision ensure that it is non-competitive . We consider a pure monopoly. The infrastructure provider is of course aware of the impact of his decisions on the price of his services, but he may or may not appreciate their impact, on demand for labor (in a market where he competes with all other industrial and agricultural producers) and wages and induced effects on demand for infrastructure itself. He may in short be a nave or a sophisticated decision-maker.
We model the nave infrastructure provider after Venables (1996). Venables portrays a producer of intermediates who derives the demand curve for his product on the assumption that his customers have already contracted for their purchases of other inputs, specifically labor. Similar beliefs on the part of our infrastructure provider generate an equilibrium that is unique in the closed economy. In the small open economy, on the other hand, equilibria, where they exist , will generally be multiple: at any world price, there will generally exist one at a low level with unexhausted scale economies and another at a high level where these have been exhausted.