STEP-BY-STEP ANSWER:
Step 1: Recognize that public goods are non-excludable, meaning individuals cannot be prevented from using them.
Step 2: Understand that because consumers can benefit without paying, there is an incentive to rely on others for the provision.
Step 3: Explain that this reliance leads to the free rider problem, where too few people may contribute voluntarily to fund the provision of the public good.
Step 4: Conclude that the free rider problem can result in the under-provision of the good compared to the socially optimal level.
Final Answer: The free rider problem undermines efficient public goods provision by reducing the incentive for individuals to contribute voluntarily, leading to potential market failure.