There's enough documented cases where we KNOW this is the case to think this is likely true for a very large proportion of them. Dick Francis is a major case in point; his wife wrote most of "his" books.
A lot of my older male patients basically fall apart when their wives pass, and not from sadness, but usually it's a complete inability to take care of themselves. A lot of men from previous generations simply refuse to or do not know how to do basic things like wash their clothes or cook their own food. I imagine it's harder to be productive when you are filthy and eating nothing but cans of cold beans everyday.