Durability, duration of production, growth and location

In this chapter we claim that all goods are durable and in this respect they are all capital goods by definition. Our claim builds on Frank Knight’s analysis: any durable good is capital and must thus have a future return that is intrinsically uncertain. It is this uncertain return that is the subject matter of entrepreneurial judgment, as Knight also explained. But it is not only goods that are capital. Labor is also capital, which is why it makes more sense to speak of human capital. And this, too, reflects uncertain future returns, in this case of investments in education. Even land is capital, since inaccessible land without network links to the rest of the world yields no return: it lacks capital value. The durability of capital and the rate of depreciation are key attributes of capital. Deterministic models show that if households and firms were to optimize these attributes, then the equilibrium growth rate would equal the real interest rate in a multi-good economy. We also show that a good’s durability determines the number of firms and thus the potential market form, in the case that production, transport and transaction costs jointly determine equilibrium. The greater the durability of a good is, the smaller its trading cost will be, other things being equal. Trade will keep expanding until there are no price differences between different locations for the limiting case of extremely durable goods. For goods with extreme durability and low transportation and transaction costs, the law of one market price will thus prevail.