The Price Effects of a Large Merger of Manufacturers: A Case Study of Maytag Whirlpool

摘要

In equations (1), (2), and (3) of our paper, we state that we simultaneously control for time effects, age effects, and product fixed effects. Because there is an exact linear relationship between age, time, and time at birth (a time-invariant product characteristic that will be absorbed by the product fixed effects), it is not possible to separately identify time effects, age effects, and product fixed effects (see Deaton 1997 for a discussion). As a result, the age-coefficients we plotted in Figures 1 and 2 can only be identified by an arbitrary normalization.