Are two small cars better than a mini van?

With dual-income families on the rise, it is not uncommon for families, especially those with younger children, to have a mini van and a second vehicle for one of the working spouses. But is having a mini van truly necessary? Perhaps it would be more economical (and better for the environment) to have two small cars, and for special events or trips, when a larger vehicle is necessary, rent a mini van for the day or weekend. One Ottawa blogger ponders the question: Are two small cars better than a van and a compact?