Before the rise of affordable automobiles and subways, many people used trolleys—small trains on rails that ran along ordinary streets—to get around in urban areas. On trolleys, there is a literal "free rider problem": Since the trains were right next to sidewalks, and since trolleys were wide open and never had doors, people could hop on and off very easily. How much money will a trolley lose if it is easy to ride for free? If "free riders" are a big problem, what will happen to the supply of trolley rides? What are a few things the trolley industry could do to solve the problem of free riders?

In the 1970s, kmart used blue light specials to encourage customers to flock to a particular department having a temporary sale. a spinning blue light activated for approximately 30 seconds, and then an in-store announcement informed shoppers of the special savings in the specific department. over time, loyal kmart shoppers learned to flock to the department with the spinning blue light before any announcement of special savings occurred. if kmart was employing classical conditioning techniques, what role did the spinning blue light play?

An investor purchases 500 shares of nevada industries common stock for $22.00 per share today. at t = 1 year, this investor receives a $0.42 per share dividend (which is not reinvested) on the 500 shares and purchases an additional 500 shares for $24.75 per share. at t = 2 years, he receives another $0.42 (not reinvested) per share dividend on 1,000 shares and purchases 600 more shares for $31.25 per share. at t = 3 years, he sells 1,000 of the shares for $35.50 per share and the remaining 600 shares at $36.00 per share, but receives no dividends. assuming no commissions or taxes, the money-weighted rate of return received on this investment is closest to:

Search engines generate revenue through pay-per-click (each time a user clicks a link to a retailer’s website); pay-per-call (each time a user clicks a link that takes the user to an online agent waiting for a call); or pay-per-conversion (each time a website visitor is converted to a customer)