Since drug companies have monopoly power and can sell their drugs far above marginal cost, they would be willing to part with their goods at any price above marginal cost. This would be a form of price discrimination, in which drug companies would charge high prices in countries like the US where people have a high willingness to pay, and low prices in poorer countries. Theoretically, price discrimination between rich and poor countries increases the overall profits of drug companies and makes drug development more lucrative. If this pricing strategy were implemented widely, we would expect to observe a strong positive correlation between a country's average drug price and per capita income. According to Maskus (2001), What is the evidence from real-world drug markets? Does the evidence support or against the theory?