* Reference: Chapter 4 of
* Jeffrey M. Wooldridge, Introductory Econometrics: A Modern Approach,
* South-Western College Publishing, 2000.
SAMPLE 1 128
READ (RENTAL.shd) city year pop enroll rent rnthsg tothsg avginc &
  lenroll lpop lrent ltothsg lrnthsg lavginc clenroll clpop &
  clrent cltothsg clrnthsg clavginc pctstu cpctstu y90 
SET MISSVALU=-999
SET SKIPMISS

* Problem 4.4, p. 155
* Restrict the sample to 1990
SET NOWARNSKIP
SKIPIF (year.eq.80)
* Log transformations
GENR lrent=LOG(rent)
GENR lpop=LOG(pop)
GENR lavginc=LOG(avginc)
OLS lrent lpop lavginc pctstu
STOP