"Do business accelerators add value? If so, how? We investigate these questions by focusing on Start-Up Chile, a government-backed ecosystem accelerator. Using a regression discontinuity design, we show that entrepreneurship-schooling services of accelerators can significantly increase new venture performance by improving the entrepreneurial capital of participants. We speculate about the existence of four performance-enhancing mechanisms: greater social clout, the provision of an accountability structure that induces entrepreneurs to articulate and reflect about specific strategic tasks, an increase in self-efficacy, and know-how about building a start-up. We find no support for causal effects of basic services of cash and co-working space."