Table 2.

Means of Key Covariates by Attrition Status

	(1)	(2)	(3)	(4)
	Final Sample	Tested Well Could Not Be Found	Tested Well Not Used For Drinking At Baseline	Household Not Found at Follow-up
Well Arsenic Level	116	134.7	186.5**	109.0
As > 50 ppb	0.61	0.74	0.68	0.67
# Household members	5.3	5.6	5.4	4.9
Household head: age	46	46.4	50.2**	44.0
Household head: read/write	0.39	0.56**	0.46	0.47
Household head: secondary education or above	0.21	0.31	0.29	0.27
Household head: woman	0.19	0.16	0.17	0.25
Number of adult females	1.7	1.8*	1.9*	1.4**
Number of children	3.1	3.3	3.4*	2.7
Fraction of members > 10 can read/write	0.55	0.63*	0.62**	0.57
Fraction of 6–14 in a household in school	0.76	0.82	0.70	0.81
Well network size	1.3	1.6	1.3	1.2
Value of food consumed: monthly 1	5.1	6.1*	6.6	4.5**
Total expenditure: monthly 1	5.9	7.2*	7.9*	5.4*
Typical income: monthly 1	7.6	8.4	11.1*	6.4***
Expenditure on medicines: monthly 1	0.54	0.82	1.1	0.57
Uses sanitary latrine	0.8	0.73	0.79	0.78
Pakka house or pakka walls (good quality)	0.11	0.15	0.25**	0.16
Fraction of members with symptoms of As poisoning	0.01	0.01	0.01	0.01
Any member with symptoms of As poisoning	0.04	0.06	0.06	0.03
Mean # days of illness last year (ages 6 to 70) 2	19	14.9*	18.1	15.5
# of observations	533	78	72	63

Source: Author’s calculations from baseline survey data (Spring 2008).

¹All income and expenditures are derived from simple questions about aggregates. All monetary units are in Bangladesh Takas (BDT). The PPP exchange rate was 22.64 BDT per dollar [44].

²Number of days lost to work or school in the last year.

³Asterisks indicate significance at the 1 (***), 5 (**) or 10 (*) % level of the difference in means of the attritted sample relative to the final sample. Significance levels were determined using standard errors that are robust and adjusted for intra-cluster correlation.