The assumption being made, and which you're still making here, is the jump from "there are benefits to registering with a disability" -> "differences in registr

The assumption being made, and which you're still making here, is the jump from "there are benefits to registering with a disability" -> "differences in registration rates are due to fraud". Certainly one possible explanation, but "obviously people would abuse that, thus this is abuse" is still an assumption, not an evidenced claim.