A marketing manager has developed a regression model to predict quarterly sales of his company's down jackets based on price and amount spent on advertising. An intern suggests that he include an indicator (dummy) variable for the fall quarter.

(a) How would you code such a variable? (What values would it have for each quarter?)
(b) Why does the intern's suggestion make sense?

Zara, a global retail and apparel manufacturer based in spain that has successfully implemented this idea by having a continuous flow of new products that are typically limited in supply. zara has created a system that draws its clientèle into its stores, on average, 17 times per year as compared to 4 times per year for most stores. how is zara using it to gain competitive advantage? what specific technologies are used by zara to maintain this advantage over its competition?