This exercise examines a supply and demand model for edible chicken, which the U. S. Department of Agriculture calls ‘‘broilers.’’ The data for this exercise is in the file newbroiler.dat, which is adapted from the data provided by Epple and McCallum (2006).7

(a) Consider the demand equation lnðQtÞ ¼ a1 þ a2lnðYtÞ þ a3lnðPtÞ þ a4lnðPBtÞ þ edt where Q ¼ per capita consumption of chicken, in pounds; Y ¼ real per capita income; P ¼ real price of chicken; PB ¼ real price of beef. What are the endogenous variables? What are the exogenous variables?