Which of the following transactions are included in gross domestic product, and by how much does each raise GDP?
a. Smith pays a carpenter $\$ 50,000$ to build a garage.
b. Smith purchases $\$ 10,000$ worth of materials and builds himself a garage, which is worth $\$ 50,000$.
c. Smith goes to the woods, cuts down a tree, and uses the wood to build himself a garage that is worth $\$ 50,000$
d. The Jones family sells its old house to the Reynolds family for $\$ 400,000$. The Joneses then buy a newly constructed house from a builder for $\$ 500,000$.
e. You purchase a used computer from a friend for $\$ 200$.
f. Your university purchases a new mainframe computer from IBM, paying $\$ 25,000$.
g. You win $\$ 100$ in an Atlantic City casino.
h. You make $\$ 100$ in the stock market.
i. You sell a used economics textbook to your college bookstore for $\$ 60$.
j. You buy a new economics textbook from your college bookstore for $\$ 100$.