Considerable time and money are being invested around the world in the belief that accelerators stimulate the growth of promising impact-oriented ventures. However, the current stock of evidence is inadequate to fully support this belief. The analyses in this chapter tackle this problem. While there are many ways that accelerators might justify the resources that are spent running them, a common set of expectations relates to their ability to stimulate short-term revenue, employment, and investment growth. The application and follow-up data introduced in Chap. 3 provide evidence of systematic short-term growth advantages for ventures that participate in accelerators compared to those that are rejected during the various selection processes. These accelerator effects are evident when looking at continuous variables measuring average year-over-year growth outcomes and categorical variables indicating positive versus negative growth. They are also evident among the very top-growing ventures in the sample. Even after accounting for the different starting points of participating and rejected ventures, accelerator program effects are still evident in the EDP data. This presents an optimistic first look at the effects of acceleration and a solid foundation for the analyses in the remainder of the book.