Wait - you already knew that?
Hardly surprising. Definitively positive results on the efficacy of ABA in early intervention of children with autism have now been available for 50 years.
Wolfe, Risley and Mees published their research in 1964, "Application of operant conditioning procedures to the behavioral problems of an autistic child". Lovaas et al published their research findings in 1973, followed by Fenske, Zalenski, Krantz and McLannahan in 1985; Lovaas again in 1987; Celiberti, Alessandri, Fong & Weiss in 1993; Maurice, Green and Luce in 1996.
Yes, there is a lot of speculation and debate as to the various causes of autism and the reasons for its rise in prevalence. But in terms of answering the question "does ABA work for autistic children" there is plenty of good science that provides us with a very defininitive "Yes!" How much evidence do we need?
Legislators of course face a lot of competing demands for public funds, and autism funding is scary. Here's a dragon that's on the rise, arguably becoming widely epidemic, and very costly to deal with effectively: typical costs of an ABA program in the preschool years run in the range of $50-60,000 per year. Legislators aren't traditionally met with smiling faces when they follow such a dragon into bankruptcy. So it's easy to raise the question (as they seem to be doing in Texas right now, though of course the same conversation is happening everywhere) of whether it makes sense to reduce or eliminate that funding dragon.
Logically, we know that it doesn't make sense. The long term costs of not providing this funding should be obvious. Families are faced with bankruptcy and/or severe stress levels; children face abuse and in extreme cases violence; and even if you don't take into account the human side of it, the cold hard economic costs alone of a lifetime of lost productivity should make the case very compelling - it's a sound investment. (And truthfully we know our governments have devised numerous, far worse ways of frittering way our tax dollars.)
The problem I think is that legislators often see only a line item on their departmental budget, and don't have all the competing costs at hand. In such a context, why would they choose to chase the dragon's tail by funding ABA programs?
If you happen to live in a jurisdiction that sees the value in fully funding ABA, count yourself fortunate. ABA is expensive, no question, and of course anything we can do to reduce those costs while improving or maintaining quality of service is important. And by all means, we need to continue to work towards understanding what's truly behind the rising prevalence.
But there is now 50 years worth of really good science telling us that ABA is worth the cost.