THE child support scheme, which underwent a major reform in 2008, is so complex that only a handful of experts can understand the rules, a study shows.

Most of the 1.5 million divorced and separated parents who pay or receive child support have no idea how the calculations are worked out, and most of those who claim to know the rules are wrong.

Confused ... most of the 1.5 million divorced and separated parents who pay or receive child support have no idea how the calculations are worked out, and most of those who claim to know the rules are wrong. Credit:Jessica Shapiro

''The new scheme was intended to reflect the complexity of modern families, but it is so complicated that hardly anyone understands it,'' said the lead investigator Bruce Smyth, an associate professor in demography and social research at the Australian National University.

As a result of this, it was unlikely many parents were using their children as pawns to extract the most financial gain from the system, despite widespread perceptions to the contrary, he said.