* Reference: Chapter 15 of
* Jeffrey M. Wooldridge, Introductory Econometrics: A Modern Approach,
* South-Western College Publishing, 2000.
SAMPLE 1 3010
READ (CARD.shd) id nearc2 nearc4 educ age fatheduc motheduc weight &
  momdad14 sinmom14 step14 reg661-reg669 south66 black smsa south &
  smsa66 wage enroll KWW IQ married libcrd14 exper lwage expersq 

SET MISSVALU=-999
SET SKIPMISS
SET NOWARNMISS 

* Example 15.4 
* Equation (15.32), p. 475.
OLS educ nearc4 exper expersq black smsa south smsa66 reg662-reg669 
* Table 15.1, p. 475.
OLS  lwage educ exper expersq black smsa south smsa66 reg662-reg669
INST lwage educ exper expersq black smsa south smsa66 reg662-reg669 &     
        (nearc4 exper expersq black smsa south smsa66 reg662-reg669)
STOP