1. My wife seems to think that we should buy our children cars of their own just because most of our friends do. She seems to think we have to keep up with the Joneses
2. Keeping up with the Joneses can be very expensive. Every time your neighbor improves his home or buys a new car, you feel you have to, too.

The expression implies that one strains one’s financial resources when one tries to match or exceed the purchases or actions made by a neighbor. Jones is a common family name.