Agenda 2030 is clear in its ambitions—everyone should be included in global progress over the next 15 years. But most discussions of progress focus on aggregated economic numbers such as gross domestic product (GDP) growth, not on the status of people. Even key measures about people such as GDP per capita are aggregated to the point that they can’t meaningfully say if people are being left behind or not.

In our background paper we describe a methodology that looks at existing indicators on people to track the status of the most vulnerable. Instead of looking at specific poverty lines, we focus on the progress of the group of people who are most likely to be left behind. Over the next 15 years, we will track progress of people in the poorest 20% globally, which we call the P20. By focusing on the conditions of a fifth of the world’s population, we will have a continuously applicable measure of inclusion, regardless of poverty lines.

This paper describes the status of existing data sources such as the World Bank’s PovcalNet, USAID’s Demographic and Health Survey, and UNICEF’s Multiple Indicators Cluster Survey. These surveys have the potential to highlight trends in the status of the P20. An analysis of the limits of these sources also highlights the need for better and more data to track the status of the P20.

We find that there are methods that can provide valuable insights about the gender, age, and subnational locations of people who are in households in the P20. However, much more needs to be done to look at intra-household dynamics and identify who is most vulnerable.