Summary statistics for psych_unit_efctv_dt variable in pos2017 dataset : Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- psych_u~v_dt | 2,375 2.00e+07 101470.7 1.98e+07 2.02e+07 by Jean Roth , jroth@nber.org , 9 Jan 2018