They're not cheating. It's because the EITC is complex so it's easy to make mistakes. Also because the IRS doesn't have the proper staffing to actually go after

They're not cheating. It's because the EITC is complex so it's easy to make mistakes. Also because the IRS doesn't have the proper staffing to actually go after people that are richer and file yet more complex tax returns. "Cheating" is a very loaded word to use here. Increasing funding so the IRS can hire the proper staff to enforce tax-law across the board is the solution and it results in net revenue for the government. But the GOP consistently opposes these measures and is intent on hamstringing the IRS in its ability to audit higher-income households and businesses.