Why is Africa so expensive?

Here is a very good Substack post by Oliver Kim, here is the key paragraph:

Intuitively, poorer countries have more of their labor forces and consumption baskets tied up in non-tradable subsistence agriculture, so when agricultural productivity grows, it lowers the price level—the exact reverse of the conventional Balassa-Samuelson relationship. But at some point, enough people have moved into manufacturing that agricultural productivity growth becomes less relevant, and the traditional upward-sloping Balassa-Samuelson relationship reasserts itself. Hence: a U-shape between incomes and prices.

A very good point, noting I would cite rent-seeking and local monopoly privilege — often more common in Africa than say Latin America or Southeast Asia — as well.

The Balassa-Samuelson relationship, by the way, is the notion that exchanges are determined by tradeables, where productivity differences are large, so non-tradeables (haircut in Mexico anyone? massage in Thailand?) are usually relatively cheap in poor, low-wage countries.  For a further explanation, do read the whole thing, and query GPT if you need to.