The US has decided to increase the cost of renouncing a US citizenship by 422%. According to the US State Department, it's about cost recovery... because the cost increased 422% between last year and this year? (Forbes):
When the news broke a year ago that the U.S. was hiking the fee to renounce U.S. citizenship by 422% there was a backlash. If anything, the uptick in American expatriations grew rather than declined. The U.S. State Department said raising the fee for renunciation of U.S. citizenship is about demand and paperwork. Perhaps, but a hike from $450 to $2,350 is still steep. That is more than twenty times the average level in other high-income countries. The State Department complains about demand on their services and all the extra workload they have to process people who are on their way out.