Hutchison Telecom provides mobile and broadband telecommunications services in Hong Kong under the brand "Three." In 2020, Three served 1.427 million post-paid customers who spent an average of HK$196 per month, and 1.852 million prepaid customers who spent an average of HK$171 per month. Post-paid service is subject to a contract that stipulates a monthly subscription charge which s/he pays at the end of the month. Pre-paid: the user pays in advance to load money onto a card which s/he utilizes until the money is uded up.

a) Explain the meaning of normal and inferior products.

b) Apply the concepts of normal and inferior products to prepaid and post-paid mobile telephone service.

c) Refer to Three's average revenue from prepaid and post-paid customers. Are the data consistent with your answer to (b)?

d) A major source of Three's revenue from post-paid customers is international roaming charges. How would Covid-19 travel restrictions have affected Three's revenues from roaming? (Here is the Google definition of roaming: Roaming charges may apply when you travel and leave your 'home' network area and 'roam' onto the network or coverage area of another provider).