Ritically evaluate statements (a) and (b):

a) The lack of clearly defined property rights means that externalities cause market failure and hence by allocating property rights to the use of natural resources, regardless of who holds these rights, will protect these resources better than government intervention.
b) The creation of a market for tradable pollution permits can achieve the socially desired pollution level by putting the responsibility for pollution control decisions into the hands of polluters themselves.

You should use diagrams where appropriate to support your arguments.