Quote from jcl:
The study is described in Kahneman's latest book "Thinking, fast and slow".
The reason of the misunderstanding you've mentioned is that there are no "risk-adjusted returns". You can not measure risk. Instead, you usually adjust the returns by some proxy of risk, like variance or drawdown. For different reasons, both are poor proxies, thus the result is highly subjective. In my opinion, using "risk-adjusted returns" makes no sense when a scientific study requires objective, reproducible data.
Doesn't that just mean that the definition of risk is "returns adjusted by variance" or "returns adjusted by drawdown"?
But, it seems like you are talking about theoretical risks as opposed to realized risk. Maybe I'm misreading your comment, but I take it to imply that a risk model would only be close to accurate if it took into account the maximum realized risk historically plus some additional quantum of risk, which would be determined in real-time via some statistical techniques.
If a trader makes 10% in a year with minimal realized risk are we not able to say that his realized risk was his actual risk for that year? Do we have to assume that at any time he was in a trade a black swan could have occurred, wiping out his 10% gains and more? Every time I enter a trade in 2012, do I have to assume my risk is as extreme as the day of the 1987 crash? While I think that may be theoretically correct, it seems like an extreme position.
