A monopolist will exercise his power by restricting supply in order to charge a higher price. The cost of paying higher prices borne by the consumers is offset by the monopolist. Where the deadweight loss occurs is when other consumers choose to purchase substitute goods. There is no offset for what the monopolist receives in this case. This is what is considered the social cost of the monopoly.

There are other costs that do not show up on a typical supply and demand analysis. One cost is that resources are wasted in order to seek monopoly rents. Another cost is that the lack of competition means that firms do not have the same incentives to innovate.