Some things are so predictable. Like, when the economy is in the crapper and people don't work, there's less tax revenue:

Federal tax revenue plunged $138 billion, or 34%, in April vs. a year ago -- the biggest April drop since 1981, a study released Tuesday by the American Institute for Economic Research says.

When the economy slumps, so does tax revenue, and this recession has been no different, says Kerry Lynch, senior fellow at the AIER and author of the study. "It illustrates how severe the recession has been."

For example, 6 million people lost jobs in the 12 months ended in April -- and that means far fewer dollars from income taxes. Income tax revenue dropped 44% from a year ago.

"These are staggering numbers," Lynch says.

Big revenue losses mean that the U.S. budget deficit may be larger than predicted this year and in future years.

Here's what is not shocking: The Federal government predicted that it wouldn't lose that much.

Let me go way out on a limb here and make a prediction: Taxes will have to go up in order to make up that "lost revenue".

Another prediction: No government won't cut services during this time of "difficulty".