Mullahy (1997; ReStat)
# Load packages for robust standard errors (install them first!) library(sandwich) library(lmtest) # Load the data from the wooldridge package (install it first!) library(wooldridge) # View the names of the columns names(bwght)
## [1] "faminc" "cigtax" "cigprice" "bwght" "fatheduc" "motheduc" ## [7] "parity" "male" "white" "cigs" "lbwght" "bwghtlbs" ## [13] "packs" "lfaminc"