West Africa, an area composed of 16 countries, is one of the fastest growing regions in the world. The region has a population of over 350 million, a five-fold increase since 1950 when 73 million people lived there.
More than half of the population is under the age of 25. The region's urban population rose from 8.3% of the total in 1950 to almost 44% in 2015.
Population size, composition and distribution all have implications for what a society needs - including food, water, energy and infrastructure - and how to provide it.
Countries in West Africa have many pressing needs. Some of the reasons are insecurity, poor governance, high military spending and forgone investment.
Forces such as climate change may add pressure, causing food insecurity, economic disruption and extreme harms from floods and droughts. The region is also shifting towards renewable and green energy, creating new job opportunities.
With all these development challenges and opportunities, and limited resources, it's vital to know what to focus on. Census data is useful for making effective policy plans and tracking progress to reach goals.
The census is a nationally representative survey, and a fundamental tool to collect information on each country's population. A trained enumerator visits the home to collect information on each person living there, including their genders, ages, marital status, occupations, languages spoken, and other key pieces of basic information.
Without census data, countries are not able to measure or understand patterns of population growth or urbanisation.
The more detailed, up to date, and high quality the data, the better informed policies and programmes can be. Census data that can be disaggregated by key characteristics (broken down into more specific parts) can draw attention to disparities and inequalities.
And routine data allows countries to measure their success on key indicators such as the Sustainable Development Goals.
Many countries in west Africa, however, do not have up to date census surveys. For example the most recent census data for Benin, Cape Verde, The Gambia, Mauritania, Niger, Nigeria and Senegal is over 10 years old. Normally these are done every 10 years.
Conducting a census is extremely challenging. It is costly and requires a large staff with training. It involves the participation of large numbers of people. There can be concerns about privacy or questions of a sensitive nature (such as ethnicity). Political instability and conflict can also make enumeration challenging.
As a public health and demography expert at the Population Council, which generates adolescent and demographic modelling data across west Africa, I've listed five reasons why the region needs up to date censuses.
Five ways a census helps a country
Allocation of resources and political power: With growing populations and economies, fresh census data helps governments allocate resources, target services, plan infrastructure projects, and direct investments.
To ensure that people have fair access to what they need, it's useful to have information about their age, income and other characteristics. This information is also used to create geographic areas containing around the same number of people, so that all voters are represented.
Economic development: The census asks households for information about their income, employment and demographic characteristics such as age or sex. This can help governments understand patterns of economic growth and how to stoke economic development. The private sector and governments need information like this for decisions about investment.
Social welfare: Census data provides a better understanding of the needs of different groups in society, such as the elderly, children, and people with disabilities. It informs the design of social welfare programmes that target those who are most in need.
For example, only three countries out of 15 in the regional body ECOWAS have ratified the African Union's protocol on disability inclusion.
Disaster response and risk reduction: Census data is also used in disaster planning, response and risk reduction efforts. It provides information on population density, vulnerability and infrastructure, which is vital in identifying areas that are at risk during extreme events such as floods. It can also indicate where vulnerable groups, such as the elderly or people with disabilities, may be harmed.
Research to inform policies: High quality, up to date, and routine census data is critical for informing research to generate the evidence that policies and programmes are based on.
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For example, the region could benefit from research on how to minimise schooling disruptions due to climate, target areas with low enrolment rates, and use technology to advance education outcomes.
Health research is another critical area, to protect children and their families and build hospitals and facilities where they are most needed.
The census can identify burden of disease, patterns of sickness and death and the distribution of risk factors. Census data can uncover disparities in health, education, social and economic programming.
Challenging but worth it
Accurate and timely census data is critical for west Africa to achieve its potential and mark progress. Conducting a census takes time, money and people, and it can be challenging to collect accurate data in certain settings.
However, the census is a critical tool to allow countries to make informed decisions about how best to allocate resources, plan for the future, and improve the lives of their citizens, including the rising generation of young people.
Jessie Pinchoff, Associate researcher, Population Council
