I see that the effect is concentrated in households with a car, but I wonder how much of this is due to the car seats themselves, and how much is due to the vast array of things designed for a “family of 4.” Restaurants take twice as long to seat a table of 5 vs. 4, venues have policies like “one free child per adult,” etc.... when we became a family of 5 everything immediately got much higher-friction. And we knew it was going to happen, and strongly considered not having a third kid because of it. Interestingly we are now considering a fourth kid because we’ve already eaten the cost of going to this high-friction lifestyle like getting the minivan.