They are held all the time. You haven't lived until you go through a RIF.
Why do you ask?
Hey, I even went through the abolition and dismantlement of a Department, as well as the creation and set up of a new major government agency.
There are all sorts of experiences to have as a government employee.
Ever been drafted?
Then there's retirement.
These are serious times. There isn't enough money in the World to pay for the debt and unfunded liabilities of the Federal Government. That doesn't include the state and local governments. People should be fired, they have to be. Any talks that do not include elimination of large portions of the Federal workforce are on their face not serious.