  Power corrections to hadronic event shapes are estimated using a recently
suggested relationship between perturbative and non-perturbative effects in
QCD. The infrared cutoff dependence of perturbative calculations is related to
non-perturbative contributions with the same dependence on the energy scale
$Q$. Corrections proportional to $1/Q$ are predicted, in agreement with
experiment. An empirical proportionality between the magnitudes of perturbative
and non-perturbative coefficients is noted.
