Calculation of Power Corrections to Hadronic Event Shapes

We compute power corrections to hadronic event shapes in $e^+e^-$ annihilation, assuming an infrared regular behaviour of the effective coupling $\alpha_s$. With the integral of $\alpha_s$ over the infrared region as the only non-perturbative parameter, also measured in heavy quark physics, we can account for the empirical features of $1/Q$ corrections to the mean values of various event shapes.