I don’t know about the rest of the US of A but in MN - a highly liberal state - a youth cannot obtain a license until the age of 16. Seems to me using a data set that extends to 14 to make a point of license decline is a bit misleading.
Can Occupy Mobil be far behind?
In our state you cannot get a license at 16 without going through a mandatory drivers ed program that costs 450 or more dollars. Insurance companies run this state.
When I was stationed at Ft. Riley, KS some time back, 14 year olds could get limited driver's licenses to get them to school and back. Apparently the population density was so low in some of the bigger farming areas that it was not cost effective to provide bussing. I think a few other mid-west farming states have, or at least had, similar licensing.
Having said that, I really doubt many, if any, 14 year olds would have owned their cars.
According to the table in Wikipedia the following states offer learner's permits at 14:
AK, AR, ID*, IA, KS, MI**, MT***, ND, SD, WY.
*14 yrs 6 mos
**14 yrs 8 mos
***14 yrs 6 mos
North Dakota sitll has restricted licenses for those under the age of 16 (learner's permit at 14).
Look at the price of a new car, or even a good used car, upkeep (tougher to do yourself than in the past), and fuel, and small wonder.