I didn't hear anything about explicit cost in the lectures. I was
able to find it in the book. Chapter 12, page 245. Luckily I was
able to guess right:
Because these costs require the firm to pay out some
money, they are called explicit costs.
Its a pretty easy definition - it is just what it sounds like it is.
I wish I had chapter 12 with me though - I have to print thtem out one
at a time as we go snce I have the ebook - It would have made it a
little faster on the exam.