Significant Portion Of World's Rural Population May Not Have Been Counted, Study Claims

The global population may have been undercounted with billions not accounted for, a new study, published in the journal Nature Communications has claimed. As per the UN estimates, the current world population is around 8.2 billion and is projected to peak at over 10 billion by mid-2080. However, the researchers at Aalto University in Finland found that rural population figures in these estimates could have been undercounted anywhere between 53 per cent to 84 per cent over the study period between 1975 and 2010.

"For the first time, our study provides evidence that a significant proportion of the rural population may be missing from global population datasets," said Josias Lang-Ritter, a PhD scholar who was involved with the study.

"The results are remarkable, as these datasets have been used in thousands of studies and extensively support decision-making, yet their accuracy has not been systematically evaluated," he added.

For the study, researchers analysed the five most widely used global population datasets (WorldPop, GWP, GRUMP, LandScan, and GHS-POP) that map the planet in evenly spaced, high-resolution grid cells with population counts based on census data.

It highlighted that there were "fundamental limitations" with the national population census while gauging rural populations. Citing an example, the researchers claim that the 2012 census in Paraguay "may have missed a quarter of the population".

"Communities in remote locations or impacted by conflict and violence are difficult to access, and census enumerators often face language barriers and resistance to participation," it stated.

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Since the study focused on maps for the period 1975-2010 owing to a lack of data from later years, findings showed the 2010 datasets had the least bias, "missing between one-third (32 per cent) to three-quarters (77 per cent) of the rural population".

"While our study shows accuracy has somewhat improved over decades, the trend is clear: global population datasets miss a significant portion of the rural population. With the same basic practices in place, it's unlikely that slightly improved input data could correct for this level of bias."

The undercounting of the population could have serious ramifications as governments, international bodies and researchers rely on global population data for resource allocation, infrastructure planning disease epidemiology and disaster risk management.