alt Hacker News> Why is taxing households together the correct thing
Hypothetically if the household splits up due to a divorce its assets are divided 50:50 (this varies by jurisdiction). Usually (again depending on the jurisdiction) the lower-earning spouse also gets alimony to even up the difference in income resulting from the new situation, at least for a few years.
Clearly then the state believes assets owned and income earned by either one of the couple belong equally to both (something I agree with personally: it's called a partnership). If that's the case, how could it be wrong to tax the household as a single entity?
The fundamental question is whether the primary unit of the society is a household or an individual. If you assume that the society consists of individuals, people should be taxed individually, spouses should be allowed to choose in advance how their assets would be divided in a divorce, and alimony should only be paid to support underage children.