The journal Econometrica is spelt as I just wrote. The journal Biometrika, however, has a `k’ in place of the letter `c’. Biometrika has it right, and Pearson its founder credits Edgeworth for this:
……like a good German he knew that the Greek `k’ is not a modern `c’, and, if any of you at any time wonder where the `k’ in Biometrika comes from, I will frankly confess that I stole it from Edgeworth. Whenever you see that `k’ call to mind dear old Edgeworth.