House Budget Committee Chairman Paul Ryan did a great public service when he released his budget last week. By throwing a piece of total garbage on the table and pretending it is a real budget plan, he allowed us to see who in Washington is serious about the budget and who just says things that will push their agenda.

It is easy to see that Ryan himself could not possibly be serious about the document he put out as a "Path to Prosperity." The Congressional Budget Office analysis of the plan, which was prepared under Representative Ryan's direction, shows that all categories of government spending outside of health care and Social Security will shrink to 3.75 percent of GDP by 2050.

This 3.75 percent of GDP includes defense spending, which is currently close to 4.0 percent of GDP, not including the cost of the war in Afghanistan. Representative Ryan said that he wants to keep defense spending close to its current level. This means that we have no money left to pay for the Justice Department, the State Department, support for education, roads and other infrastructure, the Park Service, the National Institutes of Health and all the other things that we expect the federal government to do. Essentially Paul Ryan is an anarchist who is proposing to shut down the federal government.

This cannot be a misrepresentation of Representative Ryan's agenda. He put out essentially the same budget last year at which point many people pointed out the fact that he shrank most categories of government spending to zero. If that was a mistake (albeit an incredibly foolish one) he has now had a full year to reflect on his error and redesign a budget to reflect his real priorities.

Instead, he doubled down. In Representative Ryan's 2012 Path there is no room for federal funding for all the services that even conservatives expect the government to provide. Does the Republican right now want to shut down federal prisons and end border patrols as Representative Ryan's budget implies.

This is also not a case of pulling out long-term implications that have no serious meaning. It is a common and silly practice in budget debates to project out a trend for 75 or 100 years and show it leads to an untenable situation when everyone knows the trend will not continue for this long period.

However Representative Ryan cannot make this complaint. He actually touts the budget surpluses that he is able to generate in 2040 and 2050 by getting rid of most of the government. His Path to Prosperity budget document proudly compares his budget surpluses with the growing debt under the baseline path he attributes to President Obama.

Even if the Path to Prosperity lays out an absurd budget path for the years and decades ahead, Representative Ryan has nonetheless done us a valuable service with his budget. His proposal allows us to distinguish between people who are serious about budget and economic policy and people who are obviously a different agenda.

Those who pretend that the Ryan budget is a real guidepost for thinking about the budget fall into the latter category. Foremost in this group is likely to be the various Peter Peterson funded groups -- the Concord Coalition, Come Back America and the Committee for a Responsible Federal Budget -- which last year awarded Mr. Ryan a "Fiscy" based on the commitment to fiscal responsibility in his 2011 budget plan. Of course many other prominent actors in Washington's budget debate also applauded the 2011 Ryan budget for its serious approach to the country's fiscal problems.

These organizations and individuals may like Ryan's plan to give more tax breaks to the rich by reducing the top tax rate for both individuals and corporations to 25 percent. They may be impressed by his plans to dismantle Medicare and Medicaid, and eventually Social Security. Or they may be attracted by his proposal to eliminate almost the entire federal government.

But the advocates of the Ryan plan are obviously not thinking seriously about how to fashion a budget that provides basic social insurance and sustains a 21st century economy. By allowing the public to see clearly who is serious about the budget and governmental responsibilities and who is not, Representative Ryan has performed a valuable public service.