係唔係當我地borrow$去invest時, investment可增加income,
discount返之後wealth就因為investment而增加, 所以consumption都增加?
另一方面, 如果我地係lender, 咁我地future income會因為lend$有interest收而增加,
wealth所以增加,因為wealth係present income+all future income discounted, 咁consumption就增加?
咁所以maximize wealth時,如wealth增加,
income就增加, 咁income增加令consumption增加?
但假設今年我save$1000, 再lend出去, 當interest rate 10%,
一年後我有 $1100, 但我discount返呢 $1100都係得 $1000,
咁我點樣透過lend我save的$1000, 而wealth可增加呢??
咁唔係對於我而家ge wealth都係冇增加的嗎?