true or false and explain:

1. the main reasons that there are gains to be had from trade is saving on switching time?

2. The concept of sunk cost implies that it would be rational for me to spend the rest of life searching my apartment for a $20.00 bill that i mislaid?

3. Speculators serve a useful societal purpose?

4. The main thing that prevents us from exploiting gains from specialization and trade is government trade policy?