How do rationally ignorant voters and budget maximizing bureaucrats prevent the political marketplace from delivering the efficient quantity of a public good?

What will be an ideal response?

If the marginal benefit to the voter of becoming well informed about a particular policy issue is much smaller than the marginal cost of becoming well informed, the voter is likely to remain rationally ignorant about the policy and the level of any related public goods provision. The marginal benefit of providing public goods is very high to both bureaucrats and the contractors who are employed to produce and distribute the public goods. So they have a concentrated interest in lobbying politicians to direct the bureaucrats to provide more than the efficient quantity of the public good, even to where the net benefit to the economy is zero.