Why the audit rate for the rich is falling: Congressional Republicans cut IRS spending after the party took control of the House in 2011 in an effort to reduce wasteful spending. The agency also drew criticism from Republicans after the IRS said it targeted some conservative nonprofit groups in 2013. Adjusted for inflation, the 2019 IRS budget is 19% below its funding in 2010, according to the Government Accountability Office, which means fewer auditors. While most audits are done via computer, the process is far more complex for big earners, which involves more people with specialized knowledge, said Julie Roin ... at the University of Chicago. "Most people with $10 million or more are running businesses or have business interests on the side, so their income is coming from sources that are harder to audit and their deductions are coming from sources that are harder to audit," Roin said. Why isn't the audit rate for poorer Americans falling at the same rate? Concerned with fraud, Congress has made it a priority to audit filers claiming the Earned Income Tax Credit, an anti-poverty program that gives low-to-moderate working Americans money back on their taxes. In 2018, 25% of taxpayers who received EITC money didn't actually qualify. Although, ProPublica reported, the law is so complex that many erroneous EITC claims are mistakes rather than outright fraud. More than a third of all audits are of EITC recipients, according to ProPublica. And now, the counties with the highest audit rates are predominantly poor.