and became split-offs, and iii) individuals that moved out their original household to form new split-off households. Tracking rules have changed over the course of the panel rounds for all three tracking targets mentioned above.

In the first three waves, the UNPS tracked all the original households that moved away from their 2005/06 original location to any other location, although not all households of the initial sample were targeted for individual tracking in cases where any of their members moved out of the household. Individuals and the split-off households they formed were only tracked for a subsample of the original households, namely 2 households randomly selected per EA (20 percent of the original household sample). This individual tracking was meant to compensate for the losses to the sample due to attrition. This 20 percent of households from which the individuals were tracked were referred to as “split-offs tracking targets”. Moreover, of the splitoffs tracking targets, only individuals 15 years and above who were biologically related to the household head were tracked. These individuals and split-off households were found and interviewed, even if they moved beyond their original EA/parish. Once interviewed, the splitoff individuals and all members of their new household became part of the UNPS sample and were interviewed and tracked in all subsequent UNPS waves.

Starting in UNPS 2013/14, the scope of the split-off target tracking was expanded to include all households that were part of the sample as long as they were still within Uganda, regardless of distance from the original household location and whether they were original or split-offs. In those households, only members older than 15 years and identified in the previous wave as the head, the spouse, or the child of the household head were eligible for tracking. Other members were interviewed only if they were living with one of these core members. This means that if no core member is found in the last known location, the household was not interviewed even if other previous household members still lived there.

In wave 4, the sample of the UNPS was refreshed. One-third of the original sampled households were rotated out as part of the panel refresh and were no longer tracked or interviewed.

In the current UNPS setting, tracking individuals requires the completion of an individual tracking form which contains all contact information for the split-offs and/or the individual movers. The information on their new location needed for the full tracking is generally gathered from their previous household members or any other knowledgeable person. For each core member that had moved away, a tracking form is completed. Based on the information filled in this form, the mover individuals are contacted and interviewed.

Although the tracking target sample comprises only the core members of each household, all persons living with these core members are interviewed and become part of the UNPS sample. Finally, if these individuals are core members of the new split-off household, they are interviewed in the subsequent waves of the UNPS, even if they move to different locations.

# 6.1. Empirical evaluation of the cross-sectional estimates

We computed the UNPS 2015/16 estimates. Data from the previous waves are included in the analysis to identify the household dynamics (e.g., movers, immigrants, and newborns).

We calibrated the base weights (expressed in Formula 3.8) to the known sex by age class population totals using UBOS official projections for 2015 and based on the population census of 2014. The projections used to calibrate the weights are presented in Table 6.1. Hereafter, we denote these weights as calibrated GWSM base weights.

We applied the calibrated GWSM base weights to a set of variables from UNPS 2015/16 data and compared them to Uganda official statistics to assess the functioning of the weights vis-à25