Over-regulation and policy uncertainty are at the top of CEOs' worry lists around the world for 2019. The latest annual PwC survey of world business leaders has revealed that 35 percent are 'extremely concerned' about these threats to growth. Close behind in third position is the availability of key skills, with 34 percent. Protectionism also makes an appearance with 30 percent of CEOs citing the threat as a big worry, likely with an eye on the White House and its current occupants. In North America, 38 percent said they were extremely concerned about this particular threat, making it the third most common response behind trade conflicts (44 percent) and cyber threats (45 percent).