We show that perturbation theory may give reasonable numbers for the decays of the bottomonium and charmonium ground states to e⁺e^- and to \gamma \gamma . To reach this conclusion it is important to perform the resummation of logs. In particular, we obtain the value \Gamma(\eta _b (1S) \rightarrow \gamma \gamma )=0.35 \pm 0.1 ({th.}) \pm 0.05 (\Lambda _QCD) keV.

PACS numbers: 11.10.St, 12.38.Cy, 13.40.Hq, 14.40.Gx