The purpose of this essay is to discuss two approaches to inference, and how "human capital" can provide a way to combine them. The first approach, ubiquitous in economics, is based upon the Rubin/Holland potential outcomes model and relies upon randomized treatment to measure the causal effect...

In defining selection bias, we have considered only the parallel universe of the treated group or the untreated group rather than including the parallel universe of the untreated group or the treated group. This makes causal inference theories unbalanced because they were developed on one side...

John Snow and causal inference -- RStudio and R -- Regression and simulation -- Potential outcomes -- Causal graphs -- Experiments -- Matching -- Instrumental Variables -- Regression Discontinuity Design -- Panel Data and fixed effects -- Difference-in-Differences -- Integrating and generalizing...