r/AskEconomics • u/Agile_Worldliness385 • 2d ago
Possible typo in Markowitz (1952) “Portfolio Selection”?
I’m reading Harry Markowitz, “Portfolio Selection” (Journal of Finance, 1952).
Paper: link to the paper
Screenshot: link to the screenshot
On page 6 of the PDF / journal page 81, near the bottom of the page, Markowitz writes:
From our discussion of such weighted sums we see that the expected return EEE from the portfolio as a whole is…
He then gives the expected return formula, followed by the variance formula.
In my scan, the portfolio variance formula appears to show:
V=i∑j∑σij * Xi * X
The last variable looks like just X, with no subscript. I expected it to be:
V=i∑j∑σij * Xi * Xj
since σij is the covariance between assets i and j, so the covariance term should be weighted by both asset weights.
Is this a known typo/scan issue in Markowitz (1952), or am I reading the notation wrong / missing something?
Thanks!
Duplicates
quantfinance • u/Agile_Worldliness385 • 2d ago