Any intersection of offer curves at a point other than ω determines a stable equilibrium. If the two offer curves are tangential at the endowment point, then this point is indeed an equilibrium and their common tangent is the corresponding budget line.This account is based on Section 15.B of Mas-Colell et al. The illustration is their Example 15.B.1 with its Cobb-Douglas α set equal to 0·275.
