In years past and today, three generations have probably lived together mostly out of economic necessity or advantage. Sometimes a young family moves in with the older generation because the husband and wife can't afford a place of their own. Sometimes grandparents move in because they aren't well enough or can't afford to live alone anymore. Occasionally, grandparents come to take care of the children so both parents can work. In times past, and sometimes today, three generations have lived together because they all depended on the same farm or business.
