The freaknomics study is contradicted by virtually every peer reviewed study we have on child seats. Seriously, you would take the word of an economist over the expertise of the engineers who design these seats?
yossisiegel wrote:sorry, but a 3 year old is way too young to be in a booster seat. You should keep your child in a 5 point harness seat for as long as the car seat allows. My 5 year old is in a 5 point seat, and hers goes up to 65 pounds. I plan on keeping her in it until the maximum weight limit.
its 3 times safer.
2. Keep them forward facing in a five point harness until the weight of the seat, most go to 50-65 points.
It's not 3 times safer for an older child, there is data for younger children, but we do not have real world data for older children because it is uncommon to harness older children. And you cannot keep a kid in a five point until the weight limit is reached as most of the time the seats are outgrown by height long before the weight limit is reached. For example, the graco nautilus (one of the tallest seats on the market) goes up to 65 lbs, but is usually outgrown between 40 and 50 lbs. It is extremely important not to keep a kid in a harness once it's outgrown by height, there is an increase in head excursion and risk of spinal compression, it's just not safe.
I have seen children with proper belt fit in this seat (what the IIHS tests for) but it's not as common as with, say, the graco highback turbo booster. Keep in mind the IIHS tests are a guide, they use a child crash dummy to measure fit. Well, kids aren't crash dummies, so you have to evaluate the fit on your child (lap belt low on hips, touching thighs, shoulder belt midway between kneck and shoulder).