When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
By Gerda Falkner. Edited by Gerda Falkner. Author Gerda Falkner. Fabienne Zwagemakers, Plurilogue . However, certain conditions have significantly changed in the 25 years since the theory was first posited.
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.