There was a paper put out in February 2014 by Citizenship and Immigration Canada. I'm going to refer to it because I thought it was a very well written paper on parents and grandparents.
It said that they made a considerable social, cultural, and economic contribution. I'll just quickly go through it.
First of all, if a parent or grandparent is brought to Canada, they are able to help both the husband and wife go to work, which means there will be more income in the household as well as more taxes for the Government of Canada. There's also the idea of joint families. I know it's in Indian culture. I don't know which other cultures have it.