In 2020 the West African Country of Ghana will conduct a census. This is a massive undertaking. Some 60,000 people will be deployed across the country in an effort to count every single person in Ghana.     Last week, in a reporting trip to Ghana, I got a sense of what this process entails. Along with a few other journalists, I shadowed census takers, known as enumerators, as they tested their systems in a few places around Accra. This included a mental health hospital and an urban slum. The idea is to ensure that even marginalized groups are counted in this census.     On the line with me to discuss how the census will be conducted, the kinds of questions that will be asked, and how census data can be harnessed to advance national goals around sustainable development is Omar Seidu. He is the head of demographic statistics and coordinator for the sustainable development goals at the Ghana Statistical Service.    This conversation offers an interesting perspective on the kind of herculean effort that is required to conduct a census in a developing country like Ghana, and also offers a really good grounding in why a census is such a valuable undertaking to advance development goals.