 Indeed, in Herfindahl’s opinion the cartel did not have any significant effect on price.These are born out in USGS annual price data showing the annual average price of copper in US Dollar per pound (2204.3 lb per metric ton), if one adjusts for the US Consumer Price Index.Herfindahl (1959) posits that the cartel members returned to the Nash-Cournot competition once the pivotal or trigger price was exceeded.