India - Annual Survey of Industries: 2006-07

A new sampling design has been adopted from ASI 2006-07 is as under:

i) Units with 100 or more workers will be categorized as census sector and the rest of the units will be treated as sample sector, without any change in the existing criteria;
ii) In the sample sector, the units will be stratified at 4 digit level of NIC-04 in each State separately and 1/5th of the units in each strata will be selected circular systematically for coverage in each ASI subject to a minimum sample size of 6 units in each stratum;
iii) This design will ensure that the whole universe of units is covered in five years;
iv) The classification of the units in the frame into census and sample sectors should be done in the beginning of the 5-year cycle and it should not be disturbed during the course of the cycle;
v) At the end of the cycle when the data on the all the units in the frame become available the frame should be updated and then the composition of census and sample sector should be re-drafted;
vi) In respect of the new units getting registered each year of the last 4 years in the 5-year cycle, a supplementary frame has to be prepared for each year and units for coverage from this supplementary frame of each year may be selected using the same criteria as was applied to the main frame.

The sampling design has undergone changes in the past on several occasions.