http://economics.mit.edu/files/12979
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/662744/State_of_the_Nation_2017_-_Social_Mobility_in_Great_Britain.pdf
https://www.progressivepolicy.org/trade-fact-of-the-week-ilo-236-billion-in-worldwide-profits-from-forced-labor-three-quarters-of-it-from-forced-sex-work/
https://journals.sagepub.com/doi/pdf/10.1177/10242589211022550