many tax professors/economists believe that stay at home moms should be taxed based on "imputed income." The idea is that they are performing a service that should be paid. Since they are not being paid, they are cheating the government of the taxes that it should be collecting from that service.
The same concept is advocated for in real estate. For those that own homes, they could be renting those homes out instead. Since they are not, the government is being cheated from the taxes they would collect on that rental income.
This is not a far-fetched as I thought when I first heard of it. Switzerland has an imputed tax regime for property owners.