Survey measurement of open defecation in rural India
The Swatch Bharat Mission has announced the important goal of eliminating open defecation in India. One key part of the Government's guidelines to achieve this goal is a latrine use and open defecation surveillance survey. In the 69th round of the NSS, the National Sample Survey Office took the laudable step of separately asking about latrine ownership and latrine use. This permitted measurement of open defecation among people living in households that do and do not own latrines. Motivated by these developments, we ask how a large-scale sampling survey should best ask about latrine use and open defecation, in order to usefully track progress towards the Prime Minister's goal of elimination of open defecation.
We compare results of eight studies of new data from rural India, all released in approximately the past year. Because these studies used slightly different survey questions, differences in results across survey designs can suggest principles for the design of new surveys.
In particular, surveys which asked a balanced question about open defecation or latrine use, individually, for each person in the household were able to document more open defecation than survey questions that grouped household members by demographic categories. This difference is statistically significant (meaning very unlikely to be due to chance alone) and is not because of differences in overall open defecation rates across study sites.
Therefore, we recommend that any large-scale open defecation surveillance survey ask a balanced question about latrine use or open defecation, individually, for each household member. This could be done effectively and inexpensively by incorporating these questions in to a high-quality existing sample survey with a household roster.