Introduction  1

The economics of product market traps in social media  1

Product market traps in real life: Our experiment  2

1. How much are people willing to pay to access social media platforms, assuming current levels of use from other people on campus?  3

2. How much less are people willing to pay to access social media platforms

when fewer other people use them?  3

3. How much would people pay or need to be paid to turn off social media platforms for themselves and everyone else on their campus?  4

Policy implications  5

Targeted efforts to reduce negative externalities on nonusers  6

Taxes or fees  7

Broad restrictions on social media use  8

Implications for antitrust policy  8

Conclusion  8

Appendix A: Summary of policies addressing harms from social media use  9

Appendix B  10

Endnotes  10

References  10