We note that the final bin contains 86 passive galaxies, but only 3 PSBs, so the bootstrap comparison for this bin may be unreliable. Overall, assuming no systematic errors, we find evidence that massive post-starburst galaxies at $z>1$ are significantly more compact, on average, than passive galaxies of comparable mass. Repeating the analysis using the median sizes produced very similar trends. The median analysis and further tests of robustness are presented in Appendix A. Our results are consistent with the findings of Yano et al. (2016), who also found evidence that high-redshift post-starburst galaxies are very compact.

As an additional comparison, in Figure \[fig:sigma15\] we display the distribution of $\Sigma_{1.5}\equiv M_{\ast}/R_e^{1.5}$ for the three galaxy populations, measured for the redshift range $1<z<2$ and stellar masses M$_{\ast}> 10^{10.5} ~$M$_{\sun}$. Following Barro et al. (2013), we use this parameter to effectively remove the slope in the galaxy size/mass relation. Fitting a function of the form M$_{\ast} = \Sigma ~ R_e^{\alpha}$ to the passive population, we find a best fit with $\alpha=1.55$, in very good agreement with the value $\alpha=1.5$ assumed by Barro et al. (2013). A simple Kolmogorov-Smirnov (KS) test rejects the null hypothesis that passive galaxies and PSBs are drawn from 