Let's be honest: The Internal Revenue Service is nobody's favorite government agency. But as much pain as the IRS dishes out every year, it does at least provide other useful services. It also collects massive amounts of data that, after being scrubbed of any personal information, can be very useful to policymakers and concerned citizens.

Unfortunately, it appears that the IRS has decided to end one of its best data programs.

This September, the Manhattan Institute for Policy Research released a new report titled "The Great California Exodus," detailing how, over the last decade, millions of middle-class families have fled high-tax California for low-tax jurisdictions like Texas.

"Most of the destination states favored by Californians have lower taxes," the Manhattan report read. "States that have gained the most at California's expense are rated as having better business climates. The data suggest that many cost drivers -- taxes, regulations, the high price of housing and commercial real estate, costly electricity, union power and high labor costs -- are prompting businesses to locate outside California, thus helping to drive the exodus."

This is valuable information for policymakers. And this information was obtained in part from the IRS's Migration Flow data program, one of the few data sets in existence showing where Americans are moving to and from each year.

Change Maryland, a public policy nonprofit organization, issued a similar report on migration out of the Free State this summer. Its report found that between 2007 and 2012, thousands of higher-income Marylanders fled Gov. Martin O'Malley's tax hikes, changing their place of residence to nearby Virginia. The author of the Change Maryland report, Jim Pettit, was eager to follow up on his work when the new numbers were released for 2011, but they never came. When he followed up with the IRS, he was informed via email that "the program is indeed going to be discontinued."

The IRS confirmed to The Washington Examiner that the Migration Flow data program has in fact been canceled. Instead, the IRS suggested Americans could rely on the Census Bureau's Geographical Mobility data. But the census data is derived from American Community Survey and the Current Population Survey which are both, as their names suggest, just surveys. It would be as if the federal government cancelled elections and the counting of actual votes and told us to use opinion polls to pick our leaders instead. Moreover, the Change Maryland report's most interesting number -- the amount of tax revenue that Maryland lost due to outmigration -- will no longer be collected at all.

As our own columnist Michael Barone recently pointed out, more states than ever are now completely controlled by one political party or the other. We really are becoming two countries: one red-state America and one blue-state America.

Americans deserve as much information as possible about how each model is serving its citizens. It would be a shame if the IRS stopped reporting which model Americans are choosing.