SAMPLE 1 20 READ (BEEF.txt) YEAR BEEF PBEEF PCHKN INCOME PFOOD PDFL * Convert data to real terms GENR RPBEEF=100*PBEEF/PFOOD GENR RPCHKN=100*PCHKN/PFOOD GENR RINCOME=100*INCOME/PDFL * Generate a time trend GENR TREND=TIME(0) * Estimate a linear demand equation OLS BEEF RPBEEF RPCHKN RINCOME TREND * Transform data to logarithms GENR LBEEF=LOG(BEEF) GENR LPBEEF=LOG(RPBEEF) GENR LPCHKN=LOG(RPCHKN) GENR LINCOME=LOG(RINCOME) * Estimate a log-linear demand equation OLS LBEEF LPBEEF LPCHKN LINCOME TREND / LOGLOG STOP