Instant punishment, instand forgiveness after that punishment, no grudges... happy well behaved kids. Works for us...
"Time out" and "removing privileges" are of the same ilk, and are basically ineffective because they are essentially bargaining/bribing tools. There is something material to give and take, and worse, you are giving a non-thinking little child a choice when they aren't mature enough to do such things. Not that you can't do the "withdrawal" concept many times reasonably, but to have it as the prime tool has to be ineffective. (This article doesn't tell us that specifically, but I think we can read between the lines - and we see it every day.)