It is the case in both perfectly competitive and monopolistically competitive markets that other firms will enter when firms are making positive economic profits, until price eventually equals atc and economic profits are zero. despite these similarities, in a perfectly competitive market total surplus is maximized, while in a monopolistically competitive market surplus is not maximized. which of the following statements explains this difference?

Emily bought 200 shares of abc co. stock for $29.00 per share on 60% margin. assume she holds the stock for one year and that her interest costs will be $80 over the holding period. ignoring commissions, what is her percentage return (loss) on invested capital if the stock price went down 10%?

Henry crouch's law office has traditionally ordered ink refills 55 units at a time. the firm estimates that carrying cost is 35% of the $11 unit cost and that annual demand is about 240 units per year. the assumptions of the basic eoq model are thought to apply. for what value of ordering cost would its action be optimal? a) for what value of ordering cost would its action be optimal?

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?