ABSTRACT
As I’ve said in earlier chapters, the world is a complicated place. So far, each of our examples has used a single dependent variable. What affects people’s income, for example? Education served as an independent variable, affecting income. But, given that the world is complicated, what about the possibility that other variables affect one’s level of education? Education could serve, simultaneously, as an independent and a dependent variable. For example, people often achieve levels of education similar to that of their parents, simply because all children want to be like their parents (right?). Also, parents’ income may play a role in all of this: if your parents are rich, they will be more likely to pay for your college education, which might raise the probability that you will seek such an education. So now we have your parents’ education affecting their income, which affects your education, which affects your income.
