  The coefficient tau_{RR} of the two-point function of the superconformal
U(1)_R currents of N=2 SCFTs in three-dimensions is recently shown to be
obtained by differentiating the partition function on a squashed three-sphere
with respect to the squashing parameter. With this method, we compute the
tau_{RR} for N=2 Wess-Zumino models and SQCD numerically for small number of
flavors and analytically in the large number limit. We study the behavior of
tau_{RR} under an RG flow by adding superpotentials to the theories. While the
tau_{RR} decreases for the gauge theories, we find an N=2 Wess-Zumino model
whose tau_{RR} increases along the RG flow. Since tau_{RR} is proportional to
the coefficient C_T of the two-point correlation function of the stress-energy
tensors for N=2 superconformal field theories, this rules out the possibility
of C_T being a measure of the degrees of freedom which monotonically decreases
along RG flows in three-dimensions.
