The routine approach for international benchmarking is to convert construction costs into US dollars, so that at least all costs are in the same currency. Purchasing power parity is an alternative to currency conversion. The concept has been around since the 16th century, but was developed into its modern form by Gustav and used by economists ever since. It assumes that, in the absence of transaction costs and official trade barriers, identical goods will have the same price in different markets when the prices are expressed in a given currency. Turner and Townsend is the latest survey of construction prices and embraces 46 cities. They have used an identical framework for presenting their data. This makes it possible to objectively compare 2013 and 2018 costs and to see if the same conclusions reported in Langston can be replicated.