options ps=54 ls=76; data big20; infile '../../sta6208/reg_ex/big20_air_samp.prn'; input city1 $ 1-3 city2 $ 9-11 market 22-24 revenue 26-32 year 40; ln_revenue=log(revenue); run; proc mixed; class market; model ln_revenue = year / solution; random intercept year / type=un sub=market solution; run; quit;