a What is the dummy variable 属性因素: Man and woman City and country, developed country and developing country 经济环境的变化: Peace and war 淡季和旺季 风调雨顺和洪灾旱灾 All these have a good or bad influence on economy 2021/2/202021/2/20 5 ◼ What is the dummy variable 属性因素: Man and Woman, City and country, developed country and developing country 经济环境的变化: Peace and war 淡季和旺季 风调雨顺和洪灾旱灾 All these have a good or bad influence on economy