The study looked at how multinational oil companies set prices for oil they transfer internally compared to prices in regular trades. They analyzed data from the U.S. petroleum industry from 1973 to 1984. The researchers found that prices for internal transfers were different from regular trade prices in some countries, but the differences were small. These price differences did not seem to be influenced by tax rates in exporting countries. Overall, the study suggests that multinational oil companies do not set transfer prices to avoid taxes.