  We present a new, simplified analysis of the low-energy electron-positron
interaction, and use the resulting effective theory to calculate the binding
effects that contribute to the decay rate, Gamma, of orthopositronium, through
Order(alpha^3 ln(alpha) Gamma). We express the total decay rate in terms of the
annihilation rate for a free electron and positron at threshold, which has just
recently been computed to sufficient precision. Our result corrects errors in a
previous analysis.

High Energy Physics - Phenomenology