example, suppose that we are examining determinants of income. Why do some people make more money than others? The explanatory variables are likely to be things like education, years of work experience, and so on. In a large data set, researchers might also find that people with whiter teeth earn $86 more per year than other workers, ceteris paribus. (“Ceteris paribus” comes from the Latin meaning “other things being equal.”) The positive and statistically significant coefficient on the “white teeth” variable assumes that the individuals being compared are similar in other respects:
