Statistically, how safe are para-motor craft compared to other GA planes?
In the US, there are no records kept nationally, because they fly under FAR Part 103, and are, for the most part, unregulated. Neither para-motors themselves, nor their pilots are required to be certified. Para-motors are not required to be registered. In fact, there is no actual government regulation requiring training of any kind to fly a para-motor. It is recommended, but not actually required.

There is no requirement to report accidents to any governing body, beyond those of the organization (flying club) the pilot may belong to.

Pilot certification - 


  At this time, however, pilots of ultralight vehicles are not required by Federal regulation to be certificated. 


Aircraft Certification - 


  However, the FAA presently has no intent to require certification of these vehicles by Federal regulation. 


Aircraft Registration - 


  However, registration of ultralight vehicles will not be required by Federal regulation at this time.