At time t0, there may not be ... but the exercise of monopoly power incentivizes others to produce substitutes and consumers to seek them.
> In addition to the radio relay services, MCI soon made plans to offer voice, computer information, and data communication services for business customers unable to afford AT&T's TELPAK service
At time t0, there may not be ... but the exercise of monopoly power incentivizes others to produce substitutes and consumers to seek them.
> In addition to the radio relay services, MCI soon made plans to offer voice, computer information, and data communication services for business customers unable to afford AT&T's TELPAK service
E.g. MCI vs AT&T[1]
[1]: https://en.wikipedia.org/wiki/MCI_Communications#Founding