In the developing world, disease and poverty are interdependent making access to essential medicines at affordable prices even more critical. 80% of the two billion people worldwide without access to essential medicines live in low income countries. As such, competitive rivalry in the pharmaceutical industry can improve access to medicines by reducing prices and through motivating brand companies to challenge existing patent drugs and create new and improved medicines. Furthermore, upon expiration of patent drugs, competition encourages generic companies to provide less expensive alternatives of medicines.