This document summarizes a study on how endogenous cost-effectiveness analysis impacts health care technology adoption. It finds that when prices are set based on cost-effectiveness thresholds, rather than costs alone, it can lead technologies with higher costs but more demand to be adopted over those with lower costs. This is because demand allows prices and markups to exceed costs. The study uses data from the National Institute for Health and Clinical Excellence in the UK from 1999-2005 to show some evidence of reversals in adoption decisions compared to what cost-effectiveness alone would predict. It concludes more research is needed to fully understand the impact of endogenous cost-effectiveness on technology adoption decisions.