A bad habit
I overheard a friend telling his pal, "I can't break my wife of the habit of staying up until 5 in the morning.""What is she doing?", the pal asks."Waiting for me to get home."

Bad computer viruses
Economic computer viruses

INTEREST GROUP ECONOMIST VIRUS - Divides your hard disk into hundreds of little units, each of which does practically nothing, but all of which claim to be the most important part of the computer.

ECONOMETRICIAN VIRUS - Sixty percent of the PCs infected will lose 38 percent of their data 14 percent of the time (plus or minus a 3.5 percent margin of

POLITICAL THINK TANK ECONOMIST VIRUS - Doesn't do anything, but you can't get rid of it until next election.

GOVERNMENT ECONOMIST VIRUS - nothing works on your system, but all your diagnostic software says everything is just fine.

MARXIAN ECONOMIST VIRUS - Helps your computer shut down whenever it wants to.

SOVIET ECONOMIST VIRUS - Crashes your computer, but denies it ever happened.

MAINSTREAM ECONOMIST VIRUS - It claims it feels threatened by the other files on your PC and erases then in "self-defense."

CENTRAL BANK ECONOMIST VIRUS - Makes sure that it's bigger than any other file.

MULTINATIONAL CORPORATION ECONOMIST VIRUS - Deletes all monetary files, but keeps smiling and sending messages about how the economy is going to get better.

SUPPLY SIDE ECONOMIST VIRUS - Puts your computer to sleep for four years. When your computer wakes up, you're trillion more dollars in debt.

ENVIRONMENTAL ECONOMIST VIRUS - Before allowing you to delete any file, it first asks you if you've considered the alternatives