Niskanen Center — Legal Structure: 501(c)(3) nonprofit think tank (EIN 45-5308952). Also has a 501(c)(4) lobbying arm, the Niskanen Center for Public Policy (EIN 47-4946572), spun off in 2016.

NoteThe source directly confirms all three components of the claim: (1) the main organization's 501(c)(3) status and EIN 45-5308952 are explicitly stated in the infobox; (2) the existence of a 501(c)(4) lobbying arm called 'Niskanen Center for Public Policy' is confirmed in the text; (3) the 2016 spin-off date is confirmed ('created in 2016'). The only element not explicitly verified in the source is the specific EIN for the 501(c)(4) entity (47-4946572), but the source does not contradict this — it simply does not mention it. The core claims about legal structure and the 2016 creation of the 501(c)(4) arm are fully supported.