In most cities taxi fares stay the same every day and in every kind of weather. In contrast, ride services like Uber change prices more frequently with what is called surge pricing. One Halloween, some riders were shocked when they were charged far more than usual for a late evening ride from Uber. Do you think higher prices for rides on Halloween make sense from the point of view of supply and demand? Do you think it is ethical to charge a much higher price during a high-demand period like the evening of Halloween? (Uber says it always gives riders an estimate of the fare before they agree to the service.) Discuss in terms of efficiency and fairness.