The wage and employment data used in this analysis comes from the US Bureau of Labor Statistics Employment Statistics Program. Cost of living data is from the US Bureau of Economic Analysis Regional price parity Record. The researchers calculated and ranked the locations based on the adjusted mean annual income of teachers. For the purposes of this analysis, teachers include elementary, middle and secondary school teachers in public and private institutions (excluding special or subject teachers). In order to improve the relevance, only metropolitan areas with at least 100,000 inhabitants were taken into account. In addition, the metropolises were grouped into cohorts according to population size: small (100,000–349,999), medium (350,000–999,999) and large (1,000,000 or more).