You're quite right. The true value could be much lower on average than the average self report held it to be. I hadn't considered that Graeber might have under-

You're quite right. The true value could be much lower on average than the average self report held it to be. I hadn't considered that Graeber might have under-reported this phenomena if people are consistently over-optimistic. Or maybe, absent other evidence, it might make more sense to tentatively take people's self reports at face value. Or at least hold off backing some particular elaborate alternative which involves people being wrong about the things they have most information on.