What effect should each of the following have upon the demand for portable music players in a competitive market?  Explain…

What effect should each of the following have upon the demand for portable music players in a competitive market?  Explain your reasoning in each case.

 

(a) the development of improved, low-priced devices that compete with music players

(b) an increase in population and incomes

(c) a substantial increase in the number and quality of music for players

(d) consumer expectations of substantial price increases in music players