6. Because of a recent wave of jewelry store robberies, a city increases police surveillance of jewelry stores. The increased surveillance costs the city an extra $500,000 per year, but as a result, the amount of jewelry that is stolen falls. Specifically, without the increase in surveillance, jewelry with a retail value of $900,000 million would have been stolen. This stolen jewelry would have been fenced by the jewelry thieves for $600,000. What is the net social benefit resulting from the police surveillance program