Table 1.

Descriptive statistics. “p25” (“p75”) is the 25th (75th) percentile. “I” for indicator (dummy) variable. Indicator variables are naturally coded (0/1) so mean is interpretable as a proportion having the characteristic (etc.). Had TB indicates lifetime ever having tuberculosis, and is described in much greater detail in the text. Height is measured in meters. Short is 1.68 m (5 feet 6 inches) or shorter. Tall is 1.80 m (5 feel 11 inches) or taller. BMI is body mass index: (weight [kg]) ÷ (height [m], squared). TB in company is the number of recorded wartime tuberculosis cases in each company of approx. 100 soldiers; there are 304 companies. See also discussion in text.

Variable	N	Mean	SD	p25	Median	p75
Age at death	17,679	71.22	12.71	64.22	73.08	80.24
Year of birth	17,679	1838	7.724	1834	1840	1844
Age at enlistment	11,442	23.55	6.497	18.76	21.56	26.79
Had TB [I]	17,679	0.0653
Height (m)	17,653	1.72	0.0684	1.676	1.727	1.765
Short [I]	17,653	0.3097
Tall [I]	17,653	0.1302
BMI (kg/m2)	15,745	23.06	3.335	20.83	22.48	24.66
TB in company	17,679	1.474	1.557	0	1	2