It’s true that Liberia is a post-conflict country full of UN staff, who, when not struggling to help Liberia maintain its stability and get on its feet, are probably struggling to find enough things in Liberia to spend their money on. But Liberia also differs from other countries in West Africa in that the U.S. dollar is used in parallel to the Liberian dollar. Is it possible that dollarization could also contribute to higher prices?
The fact that price differences are concentrated in services, or non-tradeables, makes me suspect that the high prices are in part due to dollarization, and here is why: in a non-dollarized economy, like Ghana, which uses the cedi, if the Ghanaian government pursues a loose monetary policy, the currency will depreciate relative to the U.S. dollar. This doesn’t affect the dollar price of imported goods—these are bought in dollars, so their price in Ghana cedis will just be inflated so that the equivalent price in dollars is unchanged. Other prices in the economy, however, are sticky. Employees have contracts with set wages, and people are used to paying a given price for hiring someone to sew a dress. As a result, the price of these non-tradeables stays constant in cedis, but becomes cheaper in dollar terms.
(Note about monetary policy transmission in West Africa: In West Africa, business and consumer loans are much scarcer. So loosening monetary policy doesn’t lead to cheaper credit very quickly. It does, however, mean that cedi funds are more readily available to banks than U.S. dollar funds, which puts pressure on the exchange rate. So monetary policy transmission through exchange rates is more important in countries like Ghana, and happens more quickly, relative to transmission through interest rate mechanisms, compared to countries where large portions of the population have access to credit.)
What this means is that Ghana, if has a trend of depreciating currency, can have low overall prices in dollar terms because, in dollar terms, prices for non-tradeables have fallen. Liberia, since it is dollarized, won’t see this effect. If Liberia prints more Liberian dollars, the exchange rate may change, with the value of the Liberian dollar declining, but prices in dollars will stay the same.
This does, of course, attribute a level difference to an effect that applies to differences in rates of change, and my observations regarding prices of goods and services are anecdotal (Liberia doesn’t have good CPI data.) If you have comments on the plausibility of the theory, please comment!