When we started (1988) in transfer pricing from academia, the IRS dominant paradigm was forcing single point estimates of gross profits indicators in audit, including gross profit margin for controlled inbound distributors, and gross profit markup for controlled outbound manufacturers and service providers. The Berry ratio (gross profits/XSGA), which was introduced by Charles Berry in Du Pont, was an unspecified “fourth” method. See United States Court of Claims. E. I. Du Pont de Nemours and Company v. The United States, Nos. 256-66 & 371-66, April 18, 1978. (Cite as: 1978 WL 3449 (Ct. Cl. Trial Div.)). When we started, IRS transfer pricing economics was not bachelor's degree level, and we suspect that it has not advanced.