* * Dougherty, Introduction to Econometrics, 4th ed * Example from Section 1.4 * Simple linear regression * open data eaef21c.xls data(format=xls,org=columns) 1 540 id female male ethblack ethhisp ethwhite age s educprof educphd educmast $ educba educaa educhsd educdo single married divorced faithn faithp faithc faithj faitho asvab01 asvab02 $ asvab03 asvab04 asvab05 asvab06 asvabc height weight85 weight02 sm sf siblings library pov78 earnings $ hours tenure exper collbarg catgov catpri catse urban regne regnc regw regs * linreg earnings # constant s * * The HMIN and VMIN aren't common options, but are needed to get the regression * line extended to 0 on the X-axis to demonstrate what the regression line looks * like well outside the observed data. * scatter(style=dots,hmin=0.0,vmin=-15.0,lines=%beta,$ footer="Figure 1.7 A Simple Earnings Function") # s earnings * * Adjusted regression using deviation from mean for S * The intercept differs slightly from the text because this uses the * full-precision sample mean, rather than 13.67 which is rounded. * diff(center) s / sdev linreg earnings # constant sdev