  For the two dimensional classical XY model we present extensive high
-temperature -phase bulk data extracted based on a novel finite size scaling
(FSS) Monte Carlo technique, along with FSS data near criticality. Our data
verify that $\eta=1/4$ sets in near criticality, and clarify the nature of
correction to the leading scaling behavior. However, the result of standard FSS
analysis near criticality is inconsistent with other predictions of
Kosterlitz's renormalization group approach.
