Why Millions Are Missing From The World’s Census

SOUTHAMPTON, England — One in three Africans wasn’t counted in recent government surveys. The 2020 U.S. Census missed nearly 3 million Latino Americans. And it’s getting worse worldwide, threatening everything from hospital funding to school resources.

New research published in Science reveals what experts are calling a “quiet crisis” in population data collection. Countries worldwide are struggling to count their own people accurately, with some missing massive chunks of their populations entirely. The ripple effects potentially impact how governments allocate resources and make policy decisions.

In the United States, census data determines how more than $1.5 trillion in federal funding gets distributed annually. When people aren’t counted, that money doesn’t follow them to their communities. Schools in undercounted areas receive less funding. Hospitals get fewer resources. Transportation projects may skip over neighborhoods that appear smaller on paper than they actually are.

The COVID-19 pandemic disrupted traditional door-to-door counting methods. People increasingly distrust government institutions and worry about how their personal information might be used. Meanwhile, international funding for population surveys is drying up, leaving many developing countries unable to afford comprehensive counts of their citizens.

International support for population data collection is evaporating. The Trump administration terminated the Demographic and Health Surveys program in February 2025, a program that had provided vital health and population data across 90 countries for four decades. Often called the gold standard of internationally comparable household surveys, the program tracked everything from infant mortality to maternal healthcare access in low- and middle-income countries.

Other major donors are also pulling back. The UK, France, and the Netherlands are redirecting development assistance toward defense spending, reducing both direct bilateral aid and contributions to UN programs. This leaves many countries unable to afford comprehensive population surveys just when they’re needed most.

The Numbers Behind the Crisis

Researchers from the University of Southampton and Columbia University analyzed global census data and found alarming trends. As of July 2024, 24 countries representing about a quarter of the world’s population had yet to publish their results during the 2020 census round. Compare that to the previous decade, when 214 countries successfully completed and published census data representing 93% of the global population.

Latino Americans were undercounted by nearly 5% in the 2020 U.S. Census, which is more than triple the rate from 2010. Children under five face particular challenges, with the 2010 U.S. Census missing 4.6% of young children, or nearly one million kids. That represented the highest undercount rate for any age group.

Young children are more likely to live in poverty, and low-income families themselves tend to be undercounted. Families sometimes don’t realize that very young children should be included in census forms. Children in this age group also live more frequently in complex, multigenerational households where they might be accidentally overlooked during the counting process.

When young children aren’t counted accurately, governments can’t properly forecast future population growth or plan for educational and healthcare needs. This creates a cascading effect where today’s undercounting leads to inadequate infrastructure and services years down the line.

International conflicts make the situation even worse. War-torn countries like Lebanon, Libya, Somalia, Sudan, Syria, and Yemen couldn’t conduct proper population counts during the 2020 round. According to the UN Economic Commission for Africa, when you add up all the disruptions, from COVID delays to conflict zones to funding shortfalls, an estimated one in three Africans weren’t counted in recent census efforts.

Why People Are Becoming Harder to Count

Public trust in institutions has been declining since 2021, according to surveys by the Organisation for Economic Co-operation and Development. More people across developed countries now report low or no trust in their national governments compared to those with high trust. This skepticism directly affects census participation, especially in communities where people fear government data collection could be used against them.

In communities where people worry about deportation, having government workers knock on doors to collect census data can feel threatening rather than helpful. Privacy concerns have also grown as cyberattacks become more frequent and sophisticated. High-profile data breaches, like when Bangladesh accidentally leaked personal information for 50 million people in 2023, erode confidence in government data protection abilities.

The pandemic forced many countries to shift from traditional in-person interviews to online and phone surveys, requiring rapid adjustments that didn’t always work smoothly. Budget cuts hit statistical offices particularly hard, with 63% of countries in a 2024 UN survey reporting significant financial challenges for census operations.

Solutions with Technology

Countries are turning to new approaches to solve these counting problems. More nations plan to use existing government records—information already collected through services like voter registration, tax records, and birth certificates—instead of relying solely on traditional door-to-door surveys.

During the 2010 census round, only 5% of countries used exclusively record-based approaches. By 2030, that number is expected to double to 10%, with another 18% planning to combine government records with traditional counting methods.

Indonesia leveraged its Population Registration System to modernize its 2020 census, reducing the need for massive countrywide surveys. Turkey transitioned from traditional methods and cut census costs from $48.3 million in 2000 to $13.9 million in 2011 while actually improving data quality.

Artificial intelligence and satellite technology are also entering the picture. Researchers are using AI to identify building footprints from satellite images, helping plan census operations and estimate populations in areas that are difficult to survey directly. These methods have proven valuable in countries like the Democratic Republic of the Congo, where traditional census implementation hasn’t been possible.

But technology alone can’t solve the fundamental trust and resource problems. New approaches work best when they supplement rather than replace traditional local data collection efforts.

Rebuilding Trust

Governments need to clearly communicate how census information guides decisions about hospital locations, school funding, and transportation planning. They must also demonstrate robust data protection practices and break down traditional bureaucratic barriers to share information more effectively across departments.

One example of this is the Philippines National Statistical Authority, which has a clear government mandate to coordinate statistical activities across all departments and spearhead data-based collaborations both domestically and internationally.

Private sector companies like Microsoft, Google, and ESRI also have roles to play, but their innovations should complement rather than replace core government statistical products.

Population data might seem abstract, but the consequences of getting it wrong are immediate and concrete. When elderly populations are underestimated, healthcare systems can’t plan appropriately. When disaster strikes, emergency responders may not know where help is needed most.

Accurate population data shouldn’t be a luxury. While we have seemingly unlimited digital data streams from our daily activities, some of our most essential demographic infrastructure is deteriorating.