When explaining the time value of money (e.g. the fact that \$100 today is worth more than \$100 a year ahead), I have seen 3 arguments: impatience, risk and inflation. What about a fourth argument that I would call alternative opportunity cost:
- I could invest the \$100 today and thus obtain more than \$100 a year later. I could do that practically risk free if I want to. That makes me value a given amount today higher than the same amount in the future.
Would that make sense, or is this perhaps already implied by one or more of the first three arguments?