the data collection technique is summarized in supplementary note 1.1 and a detailed manual is available. income data is notoriously difficult to collect and the technique used is describe in supplemetary note 2.
Values for each wealth group are assumed to approximate a midpoint for that group. The use of locally defined wealth categories means that the income distributions of different LZs cannot be directly compared.
the simplified data set includes data on all the important income sources in a zone, i.e. it omits some wild foods and other very minor sources of income. the individual household data provides very detailed information, e.g. in one study 50 types of crop, 89 types of employment and 40 types of wild food were recorded.