Economic theory in general, and trade theory are replete with equivalencies. For example, it is argued that for any specific tariff one can find an equivalent ad valorem tariff; and that for any quota one can calculate a tariff equivalent. Discuss conditions or situations under which a specific and an ad valorem tariff are not equivalent. Discuss conditions or situations when a tariff and a quota are not equivalent.

Perry is a freshman, he estimates that the cost of tuition, books, room and board, transportation, and other incidentals will be $30000 this year. he expects these costs to rise about $1500 each year while he is in college. if it will take him 5 years to earn his bs, what is the present cost of his degree at an interest rate of 6%? if he earns and extra $10000 annually for 40 years, what is the present worth of his degree.?