GIVING CREDIT WHERE CREDIT IS DUE

I believe strongly in giving credit where credit is due.  Paul Krugman posted the following on his blog.  I am deeply sympathetic with the sentiment that animates it:

"1. How can we incentivize students to stop using “impact” as a verb?

2. How can we impact their writing in a way that stops them from using the word “incentivize”?

3. Can we make it a principal principle of writing that “principle” and “principal” mean different things, and you have to know which is which?

That is all."