Orbital period demographics in field and overdensity systems for the full Winter et al. (2020) sample. The left panel shows the cumulative distribution functions of orbital periods for planets around stars in overdensities (red) and the field (blue). The solid lines show the distribution for stellar systems with only a single planet (“single”), while the dashed lines show the distribution for stellar systems with more than one planet (“multi”). The p_KS and p_AD values in the bottom right corner show the results of two-sample Kolmogorov–Smirnov and Anderson–Darling tests, respectively, assessing the null hypothesis that the two samples listed in parentheses after the p_KS and p_AD values are drawn from the same population. This is ruled out at high confidence for the overdensity sample, for which the orbital periods of single-planet systems are significantly smaller than those of multiple-planet systems. For the field sample, the period distributions of single- and multiplanet systems are statistically indistinguishable. The right panel shows the cumulative distribution function of pairs of planets within the same system with period ratio ﹩{ \mathcal P }={P}_{\mathrm{out}}/{P}_{\mathrm{in}}﹩, where P_out and P_in are the periods of the outer and inner planet, respectively. Dashed lines show all planet pairs and solid lines show only adjacent planet pairs. Blue and red show the field and overdensity samples, respectively. Planetary systems in overdensities may be somewhat more closely packed than in the field, but not at high significance.