Not trying to be snarky and hope this doesn't come across that way. But wouldn't some set of funds in any sample show they've generated alpha?
This quote from page 13 of the PDF you link to.
The average retail hedge fund does not produce alpha, but in the cross-section, many retail funds produce positive alpha.
That doesn't seem very compelling.
Neither to me does this comment from the conclusion:
14.3% of retail funds produce alpha,
Isn't that the same thing as saying nearly 86 percent of retail hedge funds fail to produce alpha?
The sample size seems pretty small too.
To avoid these problems, we start our analysis in March 2012 when we first have at least 100 retail and 100 institutional funds.
Does that mean we're talking about 14 retail funds producing good alpha?
Actually I appreciate the questions. To roughly summarize your view, any sample will have some funds with alpha. The average retail hedge fund does not have alpha. Finally, the bottom 86% of retail hedge funds do not produce alpha (note I'm going to address that last point later, near the bottom of this post).
The first two sentences summarize the paper:
We use a novel fund-level measure to identify 877 retail hedge funds. On average, retail funds do not underperform, either on an absolute basis or relative to institutional funds.
In a way, I'm sidestepping your questions - I am saying they could be true for retail hedge funds, but the same questions are true for institutional hedge funds. Would you agree with that?
A key point is that I don't need to compete with Yale. If Yale could buy up the alpha from retail hedge funds, they would. Yet that alpha persists, meaning Yale has not found a way to buy it up. The summary says alpha remains, and that retail hedge funds do not underperform institutional hedge funds. We can speculate on the reasons, but it appears Yale cannot buy up the retail hedge fund alpha.
From this I conclude I am not competing with Yale - I don't need to pick better than Yale. I need to pick retail hedge funds better than other retail hedge fund investors.
One clarification, "at least 100" is a criteria, where you took it to be exactly 100. The middle of page 7 clarifies:
After removing backfill data, we have a total of 1,038 funds of which 888 are retail funds. The average retail ratio is 43.8% (median 35.5%)
And then "at least 100" appears on page 8, which is followed a few sentences later with:
Our final monthly dataset contains 2,170 total funds (877 retail funds) with an average retail ratio of 18.9%
Which also matches the summary at the start of the paper: close to 900 retail hedge funds.
Finally, I'm also a little unsure of how they've accounted for the costs. They say they're considering costs early on. And then say they're looking at net returns and considering AUM fees. But I can also read (well skim) the paper and conclude they're really looking just at alpha?
The other thing I'd be cautious about in terms of costs if I were talking with a client about this: Are all the costs of the hedge fund investment really included? E.g., the hedge fund manager's cost may be included. But is the "wealth advisor" or the CPA now needed to do the annual tax return?
I assume this paper looked at a platform - somewhere that invites both investors and hedge funds to meet each other. I assume fees are disclosed, but industry standard seems to be "2 and 20" (2% AUM fee, 20% of profits). I have not personally explored the platforms they mention in the paper, so I don't know.
I can invest without a wealth advisor, so I assume their fees are not required. If CPA fees are hourly or per form, they would impact very small investments far more than larger ones.
I think this also provides some context for the paper saying 14% of retail hedge funds had alpha. I believe "alpha" can have different meanings, but in this context meant relative to hedge fund factors. For example, private equity funds have historically beaten the S&P 500. So you could have the average PE fund not have alpha relative to other PE funds, but still have alpha relative to the public markets. And then you might use hedge fund costs to decide if that alpha persists after costs.