With funding and technical support from the Asian Development Bank, the National Statistical Office of Mongolia piloted the EDGE stand-alone survey in 2015. The principal couple, as well as a third randomly selected adult household member, were interviewed separately and to the extent possible, simultaneously, about the principal dwelling, agricultural land, livestock, large and small agricultural equipment, non-agricultural enterprises, real estate, consumer durables, financial assets, liabilities, and valuables owned by any member of the household.
A nationally-representative three-stage stratified sampling design was adopted in Mongolia. At the first stage, provinces within the different regions were selected. Enumeration areas formed the primary sampling units (PSUs) and were selected with probability proportional to size based on the dynamically updated Population Register Database. Households within each selected PSU formed the third stage sampling units and were selected following circular systematic sampling with a random start. In order to obtain a sufficient number of households with three adult household members, in accordance with the EDGE survey protocols for testing respondent selection, two second stage strata were formed:
- SSS-1comprising all households with 3 or more adults (18+), and
- SSS-2 comprising all remaining households
Achieving the second stage stratification required a recent or updated listing of households with information on the number of adults per household. In Mongolia, the information on the number of adults in the selected PSUs was available in the Population Register Database. With the available data on the number of adults in selected PSUs, households in each selected PSU were divided into SSS-1 and SSS-2 to select the desired number of sample households from each stratum. The total sample size was 3,008 households.