 ለምሳሌ, በ 19 ኛውና በ 20 ኛው ክፍለ ዘመን በሕክምናው መስክ ምርምር ለማድረግ የሚያገለግሉት ሸክሞች በአብዛኛው በአደገኛ ላይ የተንጠለጠሉ ሲሆን የተሻለ የሕክምና እንክብካቤ ጥቅሞችም ለሀብታሞች ይንከራተቱ ነበር.
For example, during the 19th and early 20th centuries the burdens of serving as research subjects fell largely upon poor ward patients, while the benefits of improved medical care flowed primarily to private patients.