Brett Arends’s ROI: I have money in an emerging markets index fund. Should I be worried about China and Taiwan?

I don’t want an emerging markets index fund in my portfolio and I don’t care who knows it.

There’s nothing intrinsically wrong with investing in emerging markets. (A new research paper from the number crunchers at hedge fund company AQR argue that they look like a great investment right now—more on that in a moment.)

And low-cost index funds…