▁monitor ▁the ▁situation , ▁to ▁pun ish ▁or ▁" san ction " ▁def ectors , ▁if ▁they ▁are ▁legit im ized ▁by ▁external ▁political ▁structures ▁to ▁co oper ate ▁and ▁self - organ ize , ▁can ▁communicate ▁with ▁one ▁another ▁and ▁share ▁information , ▁know ▁one ▁another , ▁have ▁effective ▁aren as ▁for ▁conflict ▁resolution , ▁and ▁are ▁man aging ▁social ▁and ▁e colog ical ▁systems ▁that ▁have ▁well - defined ▁boundaries ▁or ▁are ▁easily ▁monitor able . ▁ ▁Yet ▁implementation ▁of ▁reward ▁and ▁pun ishment ▁systems ▁can ▁be ▁problem atic ▁for ▁various ▁reasons . ▁First , ▁there ▁are ▁significant ▁costs ▁associated ▁with ▁creating ▁and ▁admin ister ing ▁san ction ▁systems . ▁Prov iding ▁select ive ▁re wards ▁and ▁pun ish ments ▁requires ▁support ▁institutions ▁to ▁monitor ▁the ▁activities ▁of ▁both ▁co oper ators ▁and ▁non - co oper ators , ▁which ▁can ▁be ▁quite ▁expensive ▁to ▁maintain . ▁Second , ▁these ▁systems ▁are ▁themselves ▁public ▁goods ▁because ▁one ▁can ▁enjoy ▁the ▁benefits ▁of ▁a ▁san ction ing ▁system ▁without ▁contribution ▁to ▁its ▁existence . ▁The ▁police , ▁army , ▁and ▁jud icial ▁system ▁will ▁fail ▁to ▁operate ▁unless ▁people ▁are ▁willing ▁to ▁pay ▁tax es ▁to ▁support ▁them . ▁This ▁ra ises ▁the ▁question ▁if ▁many ▁people ▁want ▁to ▁contribute ▁to ▁these ▁institutions . ▁Ex perimental ▁research ▁suggests ▁that ▁particularly ▁low ▁trust ▁individuals ▁are ▁willing ▁to ▁invest ▁money ▁in ▁pun ishment ▁systems . ▁A ▁considerable ▁portion ▁of ▁people ▁are ▁quite ▁willing ▁to ▁pun ish ▁non - co oper ators ▁even ▁if ▁they