Technical Note No. 1. An Assessment of the Young Lives Sampling Approach in Ethiopia.
Young Lives is a longitudinal research project investigating the changing nature of childhood poverty. The study is tracking the development of 12,000 children in Ethiopia, Peru, India (Andhra Pradesh) and Vietnam through qualitative and quantitative research over a 15-year period. Since 2002, the study is following two cohorts in each study country. The younger cohort or 1-year-old cohort consists of 2,000 children per study country aged between 6 and 18 months in 2002. The older cohort or 8-year-old cohort consists of 1,000 children per country aged between 7.5 and 8.5 years in 2002. The key objectives of Young Lives are: (i) to improve the understanding of causes and consequences of childhood poverty, (ii) to inform the development and implementation of future policies and practices that will reduce childhood poverty.
The sampling methodology adopted for Ethiopia is known as sentinel site surveillance system. It consists of a multi-stage sampling procedure, whereby households within a sentinel site were selected randomly, while sentinel sites were chosen on basis of a number of predetermined criteria, informed by the objectives of the study. Specifically, in the Ethiopian context sentinel sites have been selected so as to ensure that (i) the cultural and geographic diversity of the country is reflected in the sample, (ii) the urban and rural differences are captured, and (iii) the pro-poor bias of the project is fulfilled.
The aim of this report is to assess the sampling methodology by comparing the samples with two larger, nationally representative samples. This analysis serves two main purposes. First, to analyse how the Young Lives children and households compare with children in Ethiopia, in terms of their living standards and other characteristics. Second, to examine whether and how this may affect inferences between the data. We will establish to what extent the Young Lives sample is a relatively poorer or richer Ethiopian sub-population, and whether different levels of living standards are represented in the dataset. The findings can provide guidance for interpreting research that uses Young Lives data.
Our analysis will compare a number of living standard indicators from the Young Lives sample with equivalent indicators from two different nationally representative samples: the Demographic and Health Survey 2000 (DHS) (CSA 2001a) and the 2000 Welfare Monitoring Survey (WMS) (CSA 2001b).
Based on the Young Lives sampling procedure we expect to find significant biases in the Young Lives sample. The aim of Young Lives is to document child poverty. Therefore, oversampling of poor sites mainly in food-deficient areas took place. However, budgeting constraints and concerns regarding the long-term sustainability of the study meant that the rural sites selected were located in relatively better accessible areas. This is likely to have resulted in Young Lives rural households being located in wealthier sites than the typical Ethiopian rural household.
The report is structured as follows. In Section 2, we provide a brief overview of Ethiopia. Section 3, describes the Young Lives sampling approach. Section 4, presents the methodology used in our analysis. In Section 5, we briefly describe the two comparison samples. Section 6 and 7 discuss the main results from our comparison exercise. Section 8 analyses the effects of secular trends using information from the DHS 2005 sample. Finally, Section 9 concludes.
Young Lives, Department of International Development at the University of Oxford, UK. 37 pp.