“…According to the number of households purchasing a certain appliance, the appliances were divided into high-proportion, intermediate-proportion, and low-proportion appliances, with a purchasing proportion of over 50%, between 10% and 50%, and less than 10%, respectively. In addition, according to the dependence on these appliances in modern life (the level of substitutability), we divided household appliances into three categories: basic appliances (necessary appliances in daily life, such as televisions, washing machines, refrigerators, air conditioners, lamps, and conventional bathing equipment), improved appliances (appliances that can be replaced manually or with non-energy consuming tools, such as electric mops and floor mopping robots), and luxury appliances (appliances beyond the scope of people’s daily needs, which have a certain symbolism, functionality, and experience [ 44 ], such as high-end home theaters). The specific classification of household appliances is listed in Table 2 .…”