That family and household thing has me perplexed as well. It’s a 17% difference, and Family income is higher than household. Here are the Census Bureau’s definition of family and household.
Family
A group of two or more people who reside together and who are related by birth, marriage, or adoption.
Household
A household includes all the people who occupy a housing unit as their usual place of residence.
If household income were higher than family income I would get it. BUT, family income is somehow higher than household income.
So, riddle me this : How can a group of related people reside together, but not occupy the same housing unit ?