How does winning the lottery affect GDP? Is it considered an official interaction, or is it seen as more of a trade type deal?
Winning the lottery has no impact on the GDP reporting since GDP does not include transfers. Lottery winnings are a transfer as money is taken from ticket buyers, and giving to the winner. As far as how it impacts GDP growth, I imagine the presence of a lottery on net decreases GDP growth since resources go into running the lottery that could be put elsewhere.