Wells: Well Switching in Bangladesh
In carData: Companion to Applied Regression Data Sets

Description Usage Format Details Source References Examples

Data on whether or not households in Bangladesh changed the wells that they were using.

Wells

A data frame with 3020 observations on the following 5 variables.

switch: whether or not the household switched to another well from an unsafe well: no or yes.
arsenic: the level of arsenic contamination in the household's original well, in hundreds of micrograms per liter; all are above 0.5, which was the level identified as “safe”.
distance: in meters to the closest known safe well.
education: in years of the head of the household.
association: whether or not any members of the household participated in any community organizations: no or yes.

The data are for an area of Arahazar upazila, Bangladesh. The researchers labelled each well with its level of arsenic and an indication of whether the well was “safe” or “unsafe.” Those using unsafe wells were encouraged to switch. After several years, it was determined whether each household using an unsafe well had changed its well. These data are used by Gelman and Hill (2007) for a logistic-regression example.

http://www.stat.columbia.edu/~gelman/arm/examples/arsenic/wells.dat.

A. Gelman and J. Hill (2007) Data Analysis Using Regression and Multilevel/Hierarchical Models. Cambridge: Cambridge University Press.

1	summary(Wells)

 switch        arsenic         distance         education      association
 no :1283   Min.   :0.510   Min.   :  0.387   Min.   : 0.000   no :1743   
 yes:1737   1st Qu.:0.820   1st Qu.: 21.117   1st Qu.: 0.000   yes:1277   
            Median :1.300   Median : 36.761   Median : 5.000              
            Mean   :1.657   Mean   : 48.332   Mean   : 4.828              
            3rd Qu.:2.200   3rd Qu.: 64.041   3rd Qu.: 8.000              
            Max.   :9.650   Max.   :339.531   Max.   :17.000