The ACS offers information about America’s population, households and workforce, with an annual sample size of around 3.5 million addresses. Data from the survey is used by federal, state and local decision-makers, as well as businesses, to inform planning.

In the budget for the 2023 fiscal year, US Congress directed the Census Bureau to ‘continue using the ACS as a testbed for innovative survey and data processing techniques that can be used across the Bureau’.

However, funding for the ACS has remained the same in recent years, according to the report from the Census Project, which calls for an increase from $100m to $300m.

Increasing the investment would, the authors argue, ‘protect the ACS from further data quality deficiencies, enhance non-response follow up operations, increase the survey’s sample size, reduce respondent burden, and develop new data products’ and to update the survey questions to ensure it captures data about the country’s ‘increasingly complex population and households’.

‘Since we first issued this report in 2022, America’s essential data remain at risk. High-quality, trustworthy statistics are essential for our democracy,’ said the report’s introduction.

The report highlighted current limitations and challenges in the design and data dissemination of the ACS, including: its smaller sample size than its predecessor longer-form survey; suspension to data collection operations in 2002 during the peak of the pandemic; declining response rate; relatively high undercount rates of young children, racial and ethnic subgroups, and small geographic areas, risking biased statistics. 

Additionally, improving, adding, or deleting questions on the ACS involves a lengthy process, and many data users report difficulty in finding the ACS data they need, according to the report.

The Census Project co-director Mary Jo Hoeksema said: “For years, Congress has asked us for specifics on the value of the ACS and the return on investment for the nation. This report does that, and we intend to update it annually until the needed improvements for the ACS are funded by Congress.”

The Census Project issued the first edition of the status report on the ACS in 2022, after data quality challenges prevented the Census Bureau from releasing standard 2020 ACS one-year survey estimates in 2021, releasing only experimental data. The 2016-2020 ACS five-year estimates were delayed until March 2022.

Howard Fienberg, co-director of the Census Project, added: “In an era of hyper-partisanship, it would be hard to find more broad-based, national, local and non-partisan support for a government program that has proven itself to be essential in the public and private sectors. This report has the receipts.”