The Washington Post is widely known as the newspaper that uses both its opinion and news pages to constantly tell readers that we have to cut Social Security and Medicare spending because the Congressional Budget Office (CBO) predicts big deficits 10, 20, or 30 years in the future. That is why it was extraordinary to see an article in the Sunday paper telling readers that CBO is often wrong and that its scores may not always be the best basis for policy decisions.

The central theme of the piece was that the Eisenhower administration was able to commit $25 billion to building the inter-state highway system in 1956 (the equivalent of $1.1 trillion in today's economy) in part because he didn't have to get this spending scored by CBO. While this was clearly a large expenditure relative to the size of the economy, the benefits would have been very difficult for a CBO-type agency to quantify.

In pointing out the errors of scoring by CBO, the piece seriously understates the case. In 1996, after all the Clinton era increases and spending cuts had already been put into law, CBO still projected a deficit for 2000 of 2.5 percent of GDP ($420 billion in today's economy). In fact, in fiscal year 2000 we actually had a surplus of roughly the same size, implying a forecasting error of close to 5 percentage points of GDP.

This was not due to further legislative changes. The tax and spending changes over the intervening four years actually added slightly to the deficit. The problem was that CBO grossly under-estimated economic growth over this four year period and over-estimated the unemployment rate, predicting a 6.0 percent unemployment rate for 2000 when the actual rate was 4.0 percent. 

Having underestimated growth in the years 1996-2000, CBO then hugely over-estimated growth and revenue in the next decade, failing to see that the stock bubble would collapse, sending both the economy and revenue plunging. As a result, we never came close to paying off the national debt, Federal Reserve Board Chairman Alan Greenspan's big fear when he argued in favor of the Bush tax cuts in 2001.

And of course the CBO completely missed the collapse of the housing bubble and the fact that it would tank the economy. As a result, the Washington Post was highlighting concerns about the relatively small deficits of 2006-2007, while completely ignoring the bubble that was about to devastate the country.  

More recently CBO has likely been exaggerating deficit concerns by failing to fully incorporate the slowdown in health care cost growth in its projections of future spending. If this slowdown continues, then not only will near-term deficits be relatively modest, but even the longer term deficits highlighted by the Post will also be easily contained.

One issue this article gets wrong is the nature of the data at CBO's disposal. We have very reliable data on GDP dating back to the early post-World War II years. The Bureau of Labor Statistics is a reliable source of inflation data for 100 years. CBOs problem in its scoring does not stem from a lack of data.