Effects of Market Size and Competition in Two-Sided Markets: Evidence from Online Dating.

The article investigates how network effects—specifically market size (number of users on the opposite side) and competition size (number of users on the same side)—affect user behavior in online dating platforms. Through a randomized field experiment on a large heterosexual dating app, users were shown varying information about the number of men and women nearby to shift their beliefs about market and competition size. Results indicate that larger perceived market size reduces users’ likelihood to participate in searching but increases selectivity among those who do participate, particularly for male users; conversely, greater competition size leads users, especially females, to be less selective. These findings challenge conventional assumptions that larger markets always enhance participation and matching outcomes, highlighting nuanced behavioral responses with implications for platform design and growth strategies.