The enactment of an enforceable law is essentially different in nature from peaceful persuasion or other voluntaristic efforts. For instance, legal documents and public statements by officials have for decades sought to perpetuate the myth that the operation of the Internal Revenue Service is based on the "voluntary compliance" of the American people. (We do not address the morality of that operation in this section, but merely seek to grasp its nature.) Let us suppose for a moment that the vast majority of Americans render their tax payments voluntarily to the IRS—i. e., not out of fear of legal penalties, but because the services they receive in return are so worthwhile that they would have donated the same "suggested payment" even in the absence of penalties. In other words, even if the threats of fines or imprisonment were repealed tomorrow, revenue collections would not be significantly affected. How closely does this supposition match reality?

In reality, a very few individuals do indeed intentionally donate payments exceeding their legal requirements, and they clearly do so voluntarily.
In addition, there may be some who would donate the same amount even if the law were absent. For instance, a person might determine that because of the subjective value she attached to the government's services, she wished to contribute $8,192.86 to its continued operation; later, upon filling out the requisite IRS forms, she might find that by coincidence she was legally required to pay $8,192.86, exactly the amount she had intended to donate.