>> reporter: economist paul oyer has actually written a book "everything i ever needed to know aboutfrom online dating." based on his own adventures looking for love. >> so, i... i found myself back in the dating market in the fall of 2010, and immediately, as an economist, i saw that this was a market like so many others. >> reporter: well, not any old market, like the one for pants. this is a market for what economists call "differentiated goods." >> no two potential life partners are the same. every single one of them is different. from an economics perspective, searching for a partner is just cost-benefit analysis. ( laughter ) that isn't funny! ( laughter ) this is economics! >> reporter: and that analysis includes, in the lingo of economics, "search costs." >> it takes time and effort to find your mate. you have to set up your dating profile, you have to go on a lot of dates that don't go anywhere. these frictions, the time spent looking for a mate, lead to loneliness or, as i like to say, romantic unemployment. >> reporter: oyer found himself "romantically unemployed" when he