So far,we have assumed that prices,incomes,and other variables are known with certainty. However,many of the choices that people make involve considerable uncertainty. Most people,for example,borrow to finance large purchases,such as a house or a college education,and plan to pay for them out of future income.So far, we have assumed that prices, incomes, and other variables are known with certainty. However, many of the choices that people make involve considerable uncertainty. Most people, for example, borrow to finance large purchases, such as a house or a college education, and plan to pay for them out of future income