We'll start off by stipulating that noncustodial parents (usually the father) who refuse to pay support to their children even though they are able to pay should have the full force of the law brought against them to collect payment. But often, it's more complicated than that. About 70 percent of uncollected child support is owed by parents with no reported income or reported income of less than $10,000 a year. While some of these debtors may have unreported income, many are poor themselves. Moreover, when a parent is incarcerated, arrears can continue to pile up to the degree that they will never be paid back, especially with diminished job prospects facing workers with a criminal record.