This paper investigates gender differences in smoking behavior using data from the German
Socio-economic Panel (SOEP). We develop a Blinder-Oaxaca decomposition method for
count data models which allows to isolate the part of the gender differential in the number of
cigarettes daily smoked that can be explained by differences in observable characteristics
from the part attributable to differences in coefficients. Our results reveal that the major part
of the gender smoking differential is attributable to differences in coefficients indicating
substantial differences in the smoking behavior between men and women rather than
differences in characteristics.