This is the unique household identifier, that is, it uniquely identifies each household. The variable names have a wave letter prefix (a_ b_ etc) signifying that the values are different for each wave. Every person in the same household in each wave will have the same household identifier. But as the composition of households change over time, it is not possible to decide which is the “original” household across waves. So, it is not possible to provide a unique cross-wave household identifier.
FAQ
