Noticing several posts remarking on the possible illogic of requiring parents of children in foster care to pay towards that care. . .
You may remember welfare reform, which was legislated during the Clinton administration via the Social Security Act, which is also the source of most federal child welfare funding, including MA and foster care reimbursement. Long before that (I'm not certain how long) the federal government required states to seek child support from non-custodial parents as a condition of federal funding of various assistance programs. For example, if a single parent applied for MA for a child, this triggered court proceedings to determine parentage, establish custody, and determine child support (if only MA a default ruling would typically require a non-custodial parent to enroll the child in group health insurance the parent already had access to). If AFDC (later TANF) was involved, states were required to seek financial support. All of this required states to update their own statutes--no different than requiring states to, say, pass seat-belt laws in order to receive federal highway funding.
Which all basically means this: foster placement requires legal proceedings, not only to order temporary custody, but to order child support (here, indigent parents are entitled to appointed counsel in the custody proceeding but not, so far as I know, in the support proceeding. Later, when child support is enforced and parents are potentially subject to incarceration, they have lately become entitled to appointed counsel).
If some researchers have not been aware of this, then it's a good thing the topic came up, because any component of research is, of course, part of a dynamic network of interrelationships.
Sheri McMahon