Since you quoted me, I will write a bit more.
I think a subject like economics is beyond a young child no matter how gifted this child is. I am not talking about the Freakonomics type of cutesy economics, which I think it is both more accessible and not parcicularly important.
Most of the economists actually believe very similar things. Supply and demand, free market, and so on. Mostly, economists disagree about the degree of something. For exampole, how important is market failure in a certain market? If you think it is very important in health care, then you would support national health insurance. Not too important, then you would be against the Affordable Care Act. Much of these arguments are not based on theory but on how you read the evidence, which requires understanding of statistics and institutional knowlegde. This is before you bring in things like efficiency versu equality and how do you put a price on human life and suffering. Two very well respected economists could disagree and this seperates social science from science.
I am not saying there no gifted children who can handle ambiguity. I just simply don't see this kind of subject as a good use of their time. High school will be the earliest. But from what I see, there aren't many high school econ courses that are worth the time. Might as well wait for Econ 101 in college.
