QUOTE : To quantify the power of peer-group pressure, economists studied a group of Chilean street vendors, seamstresses, and other low-income “microentrepreneurs” who had received loans from a nonprofit group. These people, mostly women, met in groups every week or two to receive training and to monitor the repayment of their loans. The economists Felipe Kast, Stephan Meier, and Dina Pomeranz randomly assigned these people to different savings programs. Some were simply given a no-fee savings account; others received the account plus the opportunity at their regular meetings to announce their savings goals and then have their progress discussed. The women subject to peer scrutiny saved nearly twice as much money as the others. The result seemed to confirm the power of the group, but where did the power come from? Could these effects be achieved with a “virtual peer group”? In a follow-up experiment, instead of discussing their savings out loud at a meeting, the Chilean women regularly received text messages noting their weekly progress (or lack thereof) along with information on how the rest of the savers in their group were doing. Surprisingly, these text messages seemed to be about as effective as the meetings, apparently because the messages provided the women with a virtual version of the same key benefits: regular monitoring and the chance to compare themselves with their peers.