Ferguson admits football has been taken over by a new breed of chairmen and owners with a hair-trigger for sacking managers.
He said: "It's a different world we're in. Managers were always sacked but in most cases there was a reasonable cause. A run of bad results. But I remember Peter Reid was sacked after five games at Manchester City at the start of the season.
"Ruud Gullit was sacked a few games into one of his seasons at Newcastle. There is an instant response from chairmen which has been unusual in recent years.
"We have a new breed of chairmen and new owners. It's not the establishment we've got now. We have new owners from Americans, Chinese, Russians. How they achieved their money is not what football is used to.
"The sudden wealth (has brought) the quick reaction of chairmen to what happens on the football field."