The mark-up as a fraction of price for the profit maximizing quantity Q* for a monopolist can be expressed in the following form. Here e* represents the price elasticity of demand:
[p*-c'(Q*)]/p* = -1/e*
We can say from this
1
The mark up is higher for goods with a higher price elasticity of demand
2
The mark-up is lower for a good with a higher price elasticity of demand
3
The mark-up is constant for all price elasticities of demand
4
The mark-up is lower for goods with a lower price elasticity of demand