> # Tobit model using R > mdata <-read.table("wage.csv", header=T, sep=",") > work <-mdata[,1] > hour <-mdata[,2] > child <-mdata[,3] > age <-mdata[,4] > edu <-mdata[,5] > wage <-mdata[,6] > hinc <-mdata[,7] > year <-mdata[,8] > mydata <-data.frame(work,hour,child,age,edu,wage,hinc,year) > library(AER) > mytobit <-tobit(hour ~ edu + year + age + child + hinc, left=0) > summary(mytobit) Call: tobit(formula = hour ~ edu + year + age + child + hinc, left = 0) Observations: Total Left-censored Uncensored Right-censored 100 50 50 0 Coefficients: Estimate Std. Error z value Pr(>|z|) (Intercept) 1787.6290 1185.0082 1.509 0.1314 edu 153.3979 71.4448 2.147 0.0318 * year 94.7800 19.8669 4.771 1.84e-06 *** age -92.4573 22.7261 -4.068 4.73e-05 *** child -913.1790 394.5286 -2.315 0.0206 * hinc -76.4703 39.0119 -1.960 0.0500 * Log(scale) 7.1157 0.1099 64.754 < 2e-16 *** --- Signif. codes: 0 e***f 0.001 e**f 0.01 e*f 0.05 e.f 0.1 e f 1 Scale: 1231 Gaussian distribution Number of Newton-Raphson Iterations: 4 Log-likelihood: -453.8 on 7 Df Wald-statistic: 34.61 on 5 Df, p-value: 1.7972e-06