Perceptions matter. People make decisions, even life-altering decisions, based on what they perceive as likely to happen. To the extent that public policy affects such decisions, the perception of likely policy change can affect behavior even before the change happens — even if it ends up never happening.

Something like that seems to be happening in America — and around the world — in the two months since Donald Trump was inaugurated as president. People are making decisions based on perceptions of how he might change the country’s direction.