"We document the presence of multiple and varied constraints to small and medium firm growth. This presents both a practical problem for business training programs and a challenge to academic economists trying to identify mechanisms through which these programs may affect outcomes. External validity needs theory. This pushes researchers to narrowly defined and highly selected sample frames, which limits the potential for clear, generalizable policy prescriptions. Ultimately, larger samples, multi-arm evaluations, process documentation, and narrowly-focused, theory-supported empirical work are all needed, but the complexity of the problem limits what we learn from any single study."

"Small businesses are often believed to serve as engines for innovation, employment and social mobility, due to their flexibility in responding to new opportunities and their potential for rapid growth. In developing countries, SMEs make up a particularly large part of the economy, yet data suggests that very few small enterprises in developing countries grow into larger businesses. Researchers conducted a qualitative study of a consulting program in the Philippines designed to help SMEs expand, investigating the obstacles that consultants identified as constraints to firm growth. They found that there is no "one-size-fits-all" approach to business training - most firms have a complex, interconnected set of challenges."