  Neutron structure functions can be extracted from proton and deuteron data
and a representation of the deuteron structure. This procedure does not require
DIS approximations or quark structure assumptions. We find that the results
depend critically on properly accounting for the Q^2 dependence of proton and
deuteron data. We interpolate the data to fixed Q^2, and extract the ratio of
neutron to proton structure functions. The extracted ratio decreases with
increasing x, up to x \approx 0.9, while there are no data available to
constrain the behavior at larger x.
