The preliminary results are lower by 4.1 per cent compared to the CBS projection of 30.4 million. Another set of projections carried out by this author using reasonable assumptions produced a total population size of 30.6 million for 2021

In January 2022, the Central Bureau of Statistics (CBS) published its preliminary census results, stating that the total population of Nepal had reached 29.2 million – a figure lower than the CBS projected figure of 30.4 million. The preliminary figure is also less than the estimated figure of 30 million based on household listing prior to the enumeration of the census. The preliminary census also published data by urban/rural residence, ecological regions, provinces, districts and palikas.

There was a huge public response to the preliminary results of the population census. Questions were raised in the House of Representatives and especially at the palika level. A number of palikas raised concern as the population size reported by the CBS was nowhere near the figures produced from within the palikas.

The preliminary results are lower by 4.1 per cent compared to the CBS projection of 30.4 million for 2021. Another set of new population projections, carried out by this author using reasonable assumptions of fertility, mortality and migration levels and 2011 age sex distribution of population, produced a total population size of 30.6 million for 2021, which is 4.8 per cent higher than the CBS preliminary total of 29.2 million.

The preliminary results for the provinces have also been published by the CBS, according to which the total population of Province 1 is 5 million, Madhes Province and Bagmati each with 6.1 million, Gandaki Province 2.5 million, Lumbini 5.1 million, Karnali 1.7 million and Sudurpaschim 2.7 million. Except for Bagmati Province, the new projections for the six other provinces are slightly higher than the CBS preliminary results.

According to the CBS preliminary results, the total population of Bagmati was reported to be 6.1 million in 2021 and the new projection also shows 6.1 million. Compared to the new projections, the CBS population size is less by 0.1 million in Province 1 as well as in Lumbini Province. The CBS preliminary figures are less by 0.3 million in each of Madhes, Gandaki, Karnali and Sudurpaschim provinces.

Although the preliminary population figures for six provinces are lower than the figures shown by the new set of projections, the pattern is similar in both sets of provincial figures in that in 2021 Madhes Province has the highest population followed by Bagmati, Lumbini, Province 1, Sudurpaschim, Gandaki and Karnali in that order.

The CBS is planning to publish the final results of the 2021 round of Nepal's population census soon. In order to minimise comments from the public as well as from the local palikas and to publish robust results, it is suggested that the CBS evaluate the preliminary results very carefully. Although there are a number of methods to evaluate census results, two techniques are of special importance.

One common method of evaluating census totals is the Post-Enumeration Survey (PES). The PES employs case-by-case matching of the census and the survey to evaluate coverage and content error. It is learnt that the CBS has carried this out and hope the final results of the census will incorporate suggestions and recommendations of the PES.

The other method is demographic technique, which analyses administrative records to develop population estimates for comparison with the census. The demographic analysis provides population estimates that are independent of the census being evaluated, using data from other sources, including administrative records on demographic variables, such as births, deaths and migration, and demographic techniques such as sex ratio and survival analysis.

As some palikas have already complained that the preliminary census results for their palikas do not match the data they have; it may be worthwhile to find out how many palikas in the country have their own population data bank. Some exercise can be carried out to match these records with the census data and act accordingly.

Prior to publishing the preliminary population census results, the CBS mentioned that the total population of Nepal in 2021 would be 30 million, which was based on the number of households collected. So did the CBS carefully check these households and match them with the households on which the preliminary census results were published? May be, some of the households that were included earlier were left out later.

The 30 million figure sounds more consistent with the growth trends of Nepal's population in the last two decades. The average annual growth rate of population was 1.35% during 2001-2011, and if 30 million is nearer the truth, the corresponding average annual growth rate turns out to be 1.19% for the 2011-2021 decade.

During the last 20 years no event resulting in the loss of a large number of human beings was observed in Nepal.

The earthquake in 2015 killed about 10,000 people, but the timing does not correspond with the time of enumeration. Of course, outmigration of people for jobs abroad is a salient feature of the Nepali population, but the magnitude of this phenomenon has not changed much in the last two decades.

Another indicator is sex ratio of the population. As per the preliminary census, the sex ratio of the total male and female population is 95.9, that is, almost 96 males per hundred females. The sex ratio of Nepal's population in 2011 was 94.2. The sex ratio in Nepal has been declining gradually since 1991 when it was 99.5.

A slowly declining sex ratio means that females are living longer than males and also relatively more males are out of the country.

However, the slow pace of sex ratio decline cannot have much impact on the total population in 2021.

Census enumeration in this round was not affected in any part of the country as it was in 2001 when the Maoist insurgency disturbed enumeration in 12 of Nepal's 75 districts. Therefore, the growth trend deviation from the expected level indicates that census enumeration and its preliminary results need to be well evaluated prior to making the population figures final.

A version of this article appears in the print on August 22, 2022 of The Himalayan Times.