options ps=54 ls=76;

data one;
input serrace 6-8 year 13-16 searace 23-24 drivers 31-32 trklength 34-40 laps 46-48 road 56 cautions 63-64 leadchng 71-72;
cards;            
       1    1975       1      35    2.54     191       1       5      13
...

     151    1979      31      37     2.5     200       0       6      35 
;
run;

/* Data set one contains the data for analysis. Variable names and
column specs are given in INPUT statement. I have included ony
first and last observations */

/* The following regression model fits Ordinary Least Squares
(standard regression model). The residuals clearly show non-constant variance  */

proc reg;
model leadchng = drivers trklength laps;
plot r.*p.;
run;

/* The following model fits a Generalized Linear model,
with poisson random component, and a constant mean:
g(mu)=alpha is systematic component, 
g(mu)=log(mu) is the link function:
mu=e**alpha      */

proc genmod;
model Cautions =  / dist=poi link=log;
run;

/* The following model fits a Generalized Linear model,
with poisson random component,
g(mu)=alpha + beta1*drivers + beta2*trkength + beta3*laps  is systematic component, 
g(mu)=log(mu) is the link function:
mu=e**alpha + beta1*drivers + beta2*trkength + beta3*laps     */

proc genmod;
model Cautions = drivers trklength laps / dist=poi link=log;
run;

quit;