unit-level data of PLFS for quarterly (Apr-June 2025 to Oct-Dec 2025)

A rotational panel sampling design has been used in the survey. The rotational scheme is of two-year duration to accommodate the changes in the frame in the intercensal period, in the sense that the sampling frames for both rural and urban areas will remain unchanged for every two-year duration. In this rotational panel scheme, each selected household has been visited four times in four consecutive months – one with first visit schedule and other three with the revisit schedule. Monthly estimates were generated for successive months without any break in the series starting from the fourth month (April 2025). The rotational panel scheme ensures a 50% matching of the samples surveyed between two consecutive quarters. The quarterly estimates were generated following the Current Weekly Status (CWS) approach.

The first visit schedules are canvassed in the selected households. The selected FSUs/households were revisited in the subsequent three months, as the panel will remain in the sample for four months. During the revisit, listing and selection of households were not done afresh. Only the households selected during the first visit were revisited for the canvassing revisit schedule. At the time of revisit, if any sample household is not found, same treated as a casualty and a substitute household is not surveyed. If any sample household is found to be split, then, among the split households available in the FSU/sub-block, the household where the head/senior most member of the erstwhile household available is covered.
A stratified multi-stage design was adopted for PLFS. The first stage units (FSU) were the Urban Frame Survey (UFS) blocks in urban areas and 2011 Population Census villages (Panchayat wards for Kerala) in rural areas. The ultimate stage units (USU) were households. As in usual NSS rounds, in the case of large FSUs, one intermediate stage unit, called hamlet group/sub-block, was formed.

The sampling frame for the urban sector is the list of Urban Frame Survey (UFS) blocks as per the latest UFS and for the rural sector, it is the list of villages as per Census 2011, updated by removing those villages that are urbanized and included in the latest UFS (till the time of sample selection). To ensure uniformity in the size of FSUs and for operational convenience, large villages/UFS blocks are notionally divided into smaller units of more or less equal size, known as sub-units depending on a pre-defined criteria of population in the village or number of households in the UFS block.