INTRODUCTION
Studies of generational difference have a long pedigree in academic demography. Researchers for years have parsed core demographic and economic variables, in an effort to discern distinctive generational patterns. Their work underscores the difficulty of justifying generational claims with data because—for any given observation—age, cohort, and year are bound together inextricably. If a person born in 1990 is 28 years old in 2018 and gets married, for example, one cannot determine the effect of age (being 28), of cohort (millennial), or of period (if there is an uptick in marriages in 2018). Demographers typically try to solve for...