When CEOs or managers run firms, they must choose from a large array of possible human resource management (HRM) practices. Choosing the right HRM practices is particularly important when a firm is in its startup phase. What is right for some firms is not right for other firms. We as economists cannot show exactly what HRM practices are effective all the time for all firms – there are none. What we can assess is what sorts or practices are most effective, under what conditions, and how much they contribute to the productivity of employees. This lecture displays alternative examples, within the lens of what we do using Insider Econometrics.