For much of the last 20 years, the EPA (under both Republican and Democrat Administrations) has promulgated regulations based on data unavailable to the public – or more accurately, unavailable to anyone outside of the EPA itself.
It is no accident that the promiscuity of job-killing regulation has closely paralleled the increasing use of such “hidden” data arrangements.
Of course, the EPA counters that all their scientific data is peer-reviewed, making public release of the data redundant. What the EPA apparatchiks do not tell you is that the peers who do the reviewing are themselves quite often working almost exclusively under grants given by the EPA, making dissent a difficult, if not impossible endeavor for a scientist hoping to keep the tax dollars flowing in his direction.
After all, if your benefactor has staked billions on pursuing a narrative (such as anthropogenic climate change) would they really find themselves amused at contrarian hijinks by a scientist who is dependent upon them for his very career? If the boss says the sky is falling, you better agree or find alternate employment.