The following is IFTF's summary of Ruth Schwartz Cowan's More Work for Mother.
The book asked a simple question: why was it that, almost a century after the introduction of labor-saving technologies in the home, women spent almost as much time doing housework as their grandmothers? The answer was that while the washing machine, vacuum cleaner, and other household appliances have made individual tasks easier-- it's certainly easier to put clothes in a washing machine than to do them by hand-- the appliances have also changes who does housework, and how often those tasks are done.
First, automating housework changed standards of cleanliness. It's less work to get a shirt clean, but we now put a shirt in the laundry after wearing it one day (even if we have jobs that require virtually no physical labor). A century ago, we would have worn a shirt for three days before washing it. Put the two trends together, and the result is, as it were, a wash.
Second, it changed who did housework. Vacuuming a carpet is less work than picking it up, taking it outside, and beating it. But who used to do that work? Fathers and sons. Wealthy and middle-class women didn't do their own laundry before the invention of the washing machine: they sent it out. Cooking is easier in an age of ready-mix cakes, but a century ago, Mom would have had a couple other sets of hands working with her. Broadly speaking, labor-saving technologies feminized housework, and turned women who previously had managed housework-- delegating, supervising, and evaluating the work of washerwomen, sons and daughters-- into manual laborers.