The estimates for the use of drinking-water supply and sanitation originate from data collected by national statistics offices and international survey programmes through nationally representative household surveys and national censuses. [read more...] Survey and census data are considered to be more reliable and objective than data collected from country sector assessments or questionnaires to local officials, because they reflect the actual practices of users rather than projections based on available infrastructure. Moreover, infrastructure facilities may have fallen out of service, yet still be counted as a source of access. Finally, the use of survey data allows analysts to work with more comparable figures, and to conduct more in-depth analysis such as disaggregating the data between wealth quintiles and monitor trends over time.

The JMP assembles, reviews and assesses country data. Since the 2008 report, more than 300 datasets, a record number, has been added to the JMP database. To complement data directly from countries, for the first time, International Household Survey Network (IHSN), supplied JMP with data from 100 household surveys. [read more...]

Currently the JMP database includes 729 nationally representative household surveys and 152 Censuses. Almost all of these come from developing regions and to a lesser extent from the Commonwealth of Independent States. Since a census in many developed countries is no longer used to collect information on water and sanitation, the JMP largely relies on administratively reported data for the developed countries. The JMP database currently includes 318 administratively reported data for developed countries.