What Startup Accelerators Really Do

This article originally published at Harvard Business Review

The well-advertised boom in startups and venture capital in recent years has coincided with the emergence of new players in startup ecosystems. One of these, startup accelerators, has received a great deal of attention but also little scrutiny. Moreover, they are commonly misunderstood or mistakenly lumped in with other institutions supporting early-stage startups, such as incubators, angel investors, and early-stage venture capitalists.

In a recent analysis published by the Brookings Institution, I tackle some of the confusion around startup accelerators by laying out a clearer picture of what they do, and how they differ from other early-stage institutions. I also provide a review of the research literature on the effectiveness of accelerators to achieve their stated aims, some best practices for accelerator programs, and some figures on the size, scope, and impact of these organizations in the United States. Accelerators are playing an increasing role in startup communities throughout the United States and beyond. Early evidence demonstrates the significant potential of accelerators to improve startups’ outcomes, and for these benefits to spill over into the broader startup community. However, the measurable impact accelerators have on performance varies widely among programs — not all accelerators are created equally. Quality matters. What are startup accelerators? Startup accelerators support early-stage, growth-driven companies through education, mentorship, and financing. Startups enter accelerators for a fixed-period of time, and as part of a cohort of companies. The accelerator experience is a process of intense, rapid, and immersive education aimed at accelerating the life cycle of young innovative companies, compressing years’ worth of learning-by-doing into just a few months. Susan Cohen of the University of Richmond and Yael Hochberg of Rice University highlight the four distinct factors that make accelerators unique: they are fixed-term, cohort-based, and mentorship-driven, and they culminate in a graduation or “demo day.” None of the other previously mentioned early-stage institutions — incubators, angel investors, or seed-stage venture capitalists — have these collective elements. Accelerators may share with these others the goal of cultivating early-stage startups, but it is clear that they are different, with distinctly different business models and incentive structures.

Yet the confusion is real, including within the startup sector itself. In fact, of the nearly 700 U.S.-based organizations that were identified as an “accelerator” or “accelerator/incubator” or similar — either through self-identification or through leading investor databases — I could confirm these four criteria in fewer than one-third of them. In other words, two of every three “accelerators” are not in fact accelerators, based on this criterion.

Accelerators in the United States

Silicon Valley–based Y Combinator launched the first seed accelerator program, in 2005, in Boston, followed closely by TechStars, which was founded the next year in Boulder, Colorado. Both programs have evolved over the years and have traditionally been considered the two premier accelerator programs globally.