The real-balances, interest-rate and foreign purchases effects all explain
a) why the aggregate supply curve is up-sloping?
b) shifts in the aggregate demand curve.
c) why the aggregate demand curve is down-sloping?
d) shifts in the aggregate supply curve.

Suppose that each firm in a competitive industry has the following costs: total cost: tc=50+12q2tc=50+12q2 marginal cost: mc=qmc=q where qq is an individual firm's quantity produced. the market demand curve for this product is: demand qd=160−4pqd=160−4p where pp is the price and qq is the total quantity of the good. each firm's fixed cost is.

Who has summer school : ( because i do : (

Google started as one of many internet search engines, amazon started as an online book seller, and ebay began as a site where people could sell used personal items in auctions. these firms have grown to be so large and dominant that they are facing antitrust scrutiny from competition regulators in the us and elsewhere. did these online giants grow by fairly beating competition, or did they use unfair advantages? are there any clouds on the horizon for these firms -- could they face diseconomies of scale or diseconomies of scope as they continue to grow? if so, what factors may limit their continued growth?