Marginal changes for the many or focusing on the few? Trade-offs in firm support policies and jobs

Should governments aiming to improve job opportunities devote additional resources towards trying to provide programs that attempt to generate marginal changes in many micro and small firms, or try to target the support towards making larger impacts on a smaller number of high-growth and larger firms? For example, should a government spend an additional $5 million on grants and training programs that support 25,000 micro firms at $200 each, use it to give 100 grants of $50,000 each to 100 high-growth potential firms, or use it as a single $5 million tax incentive to encourage one large multinational to set up a manufacturing plant in the country? I’ve been asked my thoughts on this question quite a few times, so thought I’d share them here.
 
The answer involves many different trade-offs and considerations, and I attempt to summarize some of the key ones in this post. The bottom line is that there are trade-offs (at least in the short-run) between poverty alleviation and productivity growth, and that different policies will have impacts on different types of job creation. A key lesson for policymakers is to be clear about what the job problem is that they are trying to solve, and not try to use the same policy instrument to achieve multiple competing priorities.