  We use simple comparisons of the optical and radio properties of the wide
separation (3'' to 10'') quasar pairs to demonstrate that they are binary
quasars rather than gravitational lenses. The most likely model is that all the
pairs are binary quasars, with a one-sided 2--sigma (1--sigma) upper limit of
22% (8%) on the lens fraction. Simple models for the expected enhancement of
quasar activity during galaxy mergers that are consistent with the enhancement
observed at low redshift can explain the incidence, separations, redshifts,
velocity differences, and radio properties of the binary quasar population.
Only a modest fraction (< 5%) of all quasar activity need be associated with
galaxy mergers to explain the binary quasars.
