However, the UN reports that their estimate of World population has 1-2% error. An evaluation of a series of United Nations population projections between the 1950s and 1990s found that all but one had a margin of error of less than 4%. Most factors indicate an undercount. World population could be 7.4 billion or even 7.5 billion now.
Highlights Undercount now
* High population growth in Nigeria and other African countries but they have the oldest and most inaccurate Census
* China hiding many second and third children
* Various scientific studies show that assumed decreased fertility in Africa is not happening or happening more slowly which means a lot more children, so a census with missing people from ten years ago assumes smaller families but there were more
Highlights Under Projected
* Various scientific studies show that assumed decreased fertility in Africa is not happening or happening more slowly which means a lot more children. This error repeats and compounds for projections
* Small families diminish and eventually larger families are the ones left breeding
* Countries with decreasing populations will shift to pro-fertility policies to sustain workforce levels
* Africa is conquering AIDS and other diseases but the fear of AIDS would
* since the UN 2012 estimates, recent information is showing that Africa fertility is staying higher and the high estimate of 10.9 billion is more likely for 2050 than the medium 9.6 billion estimate
In Africa, however, the quality of data can pose significant problems. “Some [African] countries have very few censuses, and a number of censuses are of doubtful accuracy,” Professor Rob Dorrington, Professor of Actuarial Science at the University of Cape Town, told Africa Check.
Countries like Eritrea, South Sudan and the Democratic Republic of the Congo did not conduct population censuses between 2005 and 2014, as required by the UN for their 2010 round of projections. This year Angola conducted its first national census in 30 years, Dr Mady Biaye, Technical Advisor for East and Southern Africa at the United Nations Population Fund told Africa Check. Nigeria for example has far less accurate population recording systems. Other countries have not held censuses for decades.
In Nigeria the country’s census figures have been the subject of controversy for decades. Accusations of rigging date back to the 1950s and have continued unabated under military and civilian regimes.
The error could be even higher. The census figures for many African countries are not accurate. In some instances current population estimates are based on old census data and are little more than projections themselves.
China has the One Child policy where tens of millions of people are not registered. Their parents hide second children and they do not have State documentation. The second children are illegals in their own country. China makes more of its people illegals than the illegals from Mexico and South America in the USA. Deliberate avoidance of census takers is therefore likely to be higher in China than in other countries.
In 2012, for the second UN population revision in a row, the world’s projected population for 2050 was revised higher in the UN’s medium-fertility variant; it is now projected to reach nearly 9.6 billion in 2050, up from 9.3 billion. As in earlier revisions, there is a very important caveat to this projection: It assumes a gradual convergence in countries’ fertility rates, the main driver of demographic trends, towards 2.1 children per woman, which would lead to a roughly stable global population. But for the last several revisions, these assumptions have proven too optimistic.
The UN produces three main scenarios: Low, Middle, and High variants. The Low and High variants are similar to the Medium except that the TFR is one-half child less and one-half child more than the Medium. Under these three variants, world population in 2050 is projected at 8.3 billion (low), 9.6 billion (medium), and 10.9 billion (high). The largest variation by far is among the less developed countries.
Nigeria’s current population estimate might be 20 million low. The future population has had big upward revisions
More Data is Approximated based off of poor population data
Around 1.22 billion people live on less than a $1.25 (75p) day? Maybe, maybe not. Malaria deaths fell by 49% in Africa between 2000 and 2013? Perhaps. Maternal mortality in Africa fell from 740 deaths per 100,000 births in 2000 to 500 per 100,000 in 2010? Um … we’re not sure.
These numbers, along with most of what we think of as facts in development, are actually estimates. We have actual numbers on maternal mortality for just 16% of all births, and on malaria for about 15% of all deaths. For six countries in Africa, there is basically no information at all.
The world of development has had an odd double-think about data for decades now. On the one hand, researchers and others will freely admit to the huge gaps and problems with development data (indeed, it’s sometimes hard to get people to stop talking about it). But on the other hand, these same individuals and institutions have quite big vested interests in downplaying the unreliability of data.
An academic who has just carried out a complex piece of econometrics based on household survey data doesn’t want to be told the data is so poor that the results are pretty meaningless. An aid agency that finds malaria rates have come down in a country where there is a big malaria programme doesn’t want the party spoiled by people pointing out that these are unreliable estimates.
That might be one of the reasons why improving data has never been a big priority for the international development effort, or for national governments (with some notable exceptions). Donors aren’t funding it – the share of official aid allocated to statistical development halved between 2011-12, to a vanishingly small 0.16% of all aid.