  We analyze the proton electromagnetic form factor ratio
$R(Q^{2})=QF_2(Q^{2})/F_1(Q^{2})$ as a function of momentum transfer $Q^{2}$
within perturbative QCD. We find that the prediction for $R(Q^{2})$ at large
momentum transfer $Q$ depends on the exclusive quark wave functions, which are
unknown. For a wide range of wave functions we find that $ QF_2/F_1 \sim\
const$ at large momentum transfer, in agreement with recent JLAB data.
