Document ID: ./input/supremecourt_opinions/opinions/14pdf/13-534_19m2.pdf
Page Number: 22

Cite as:  574 U. S. ____ (2015) 

17 

Opinion of the Court 

E 
The  Board  does  not  contend  in  this  Court  that  its  anti­
competitive  conduct  was  actively  supervised  by  the  State
or that it should receive Parker immunity on that basis.

By  statute,  North  Carolina  delegates  control  over  the
practice of dentistry to the Board.  The Act, however, says 
nothing  about  teeth  whitening,  a  practice  that  did  not 
exist when it was passed.  After receiving complaints from
other dentists about the nondentists’ cheaper services, the 
Board’s  dentist  members—some  of  whom  offered  whiten­
ing services—acted to expel the dentists’ competitors from
the market.  In so doing the Board relied upon cease-and­
desist  letters  threatening  criminal  liability,  rather  than
any  of  the  powers  at  its  disposal  that  would  invoke  over­
sight  by  a  politically  accountable  official.    With  no  active 
supervision by the State, North Carolina officials may well 
have  been  unaware  that  the  Board  had  decided  teeth 
whitening  constitutes  “the  practice  of  dentistry”  and
sought  to  prohibit  those  who  competed  against  dentists 
from participating in the teeth whitening market.  Whether 
or not the Board exceeded its powers under North Carolina 
law, cf. Omni, 499 U. S., at 371–372, there is no evidence 
here of any decision by the State to initiate or concur with
the Board’s actions against the nondentists. 

IV 
The  Board  does  not  claim  that  the  State  exercised  ac­
tive, or indeed any, supervision over its conduct regarding 
nondentist  teeth  whiteners;  and,  as  a  result,  no  specific 
supervisory  systems  can  be  reviewed  here.    It  suffices  to 
note that the inquiry regarding active supervision is flexi­
ble  and  context-dependent.    Active  supervision  need  not 
entail day-to-day involvement in an agency’s operations or 
micromanagement of its every decision.  Rather, the ques­
tion  is  whether  the  State’s  review  mechanisms  provide 
“realistic  assurance”  that  a  nonsovereign  actor’s  anticom­