Why charge sliding-scale fees for government services such as health care and education?  In the United States we currently have extreme economic disparity that has been caused, at least partially, if not mainly, by government policies.  Tax regulations that benefit interest income earners and capital gains income earners over wage earners contribute to disparity.  The Federal Reserve system contributes to disparity by offering low interest rates to the wealthy and high interest rates to the poor.   Instead of trying to fix this problem of economic disparity simply by taxing the rich to redistribute wealth to the poor, the government can charge sliding scale fees. With such measures, combined with other measures such as Public Banking, eventually the economic disparity will lessen and users fees will equal out accordingly.