Look at a DOW chart beginning in Jan./1980 to present ---- no doubt 401K plans are a part of that rise ----- hard to formulate a strong case for HOW MUCH though.
One thing which really hurt me is HCE's ----- cost me a lot in early years as we could not get the 'peasants' to understand the value of FREE MONEY (match) !
Several years, I had reversals!
"It isn't to evil dictators with a lust for power that Americans have been slowly surrendering their autonomy. It is to well-intentioned authorities who believe sincerely that our freedoms must be circumscribed for our own good." ~ Jeff Jacoby