We start by assessing the comparability of these different programs in terms of course content and who takes part in the training. We find there is considerable heterogeneity across studies in both the participants studied and in the length and content of the training provided, although a number of core topics are covered in most training sessions. We next discuss a number of challenges researchers have faced in measuring impact. Critically, most of the existing studies have very low power for detecting impacts on business profits or revenues. This lack of power results from the use of a single follow-up survey to measure impacts on relatively small samples of very heterogeneous firms. Power is further compromised because take-up rates are often far below 100 percent. In addition, many existing studies only look at impacts within a year of training, which may be too short a period to detect changes. Many studies also experience problems with attrition, selective survival and start-up, and non-responses on sensitive outcomes like profits and revenues. A final concern is that training may change measurement of outcomes, even if it doesn’t change the outcomes themselves, and so we discuss how several studies have attempted to show their results are robust to reporting issues.

With these issues in mind, we then assess what we have learned about the impacts of different programs on business survivorship and start-up, business practices, and profitability and enterprise growth. Among the minority of studies which have looked at impacts on survivorship of existing businesses, there is some weak evidence for a positive effect for male-owned businesses. However, for female-owned businesses training is found to have either zero or a slightly negative effect on survivorship. Stronger results have been found with respect to the impacts of training programs on new business start-ups. All the training programs studied which have content specifically intended to help people to start a new business have found training helps firms start-up, although there is some evidence that training may merely speed up the entry of firms who were going to enter anyway, and potentially change the selection of who enters.

Almost all training programs find that treated firms start implementing some of the business practices taught by the training. However, the magnitude of the impacts is rather small in many cases, with a typical change being 0.1 or 0.2 standard deviations, or 5 to 10 percentage points. The combination of relatively small changes in business practices and low statistical power means that few studies have found any impacts of training on sales or profitability, although the studies with most power have found some positive short-term effects. Studies which work with microfinance clients have also looked at outcomes relevant to the microfinance institution. There is some evidence that training changes rates of client retention and the characteristics of loan applicants. Finally, the three studies which examine the impact of individualized consulting provided to larger firms find evidence that consulting services can improve the performance of firms, including those with multiple plants and over 200 workers.

Before concluding we discuss several important issues that existing work provides very little evidence about, but which are crucial for developing policy recommendations. These include whether gains from training are long-lasting and whether they come from competing away sales from untrained firms or through other channels. We also discuss the need to address the heterogeneity of both training content and participants, and to uncover the market failures that might prevent firms from investing in training themselves if it is really beneficial. We conclude with recommendations for future work in this area.

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