Imbalances in supply and demand often cause the price for the same good to vary across geographic locations. Economic theory suggests that if the price differential is greater than the cost of transporting the good between locations, then buyers will shift demand from high-price locations to...

The phenomenon of sponsored search advertising where advertisers pay a fee to Internet search engines to be displayed alongside organic (non-sponsored) web search results is gaining ground as the largest source of revenues for search engines. Using a unique panel dataset of several hundred...