The author is a Reuters Breakingviews columnist. The opinions expressed are his own.
At this stage, it is hard to quantify how a planned referendum on Britain's membership of the European Union is impacting investor sentiment and the outlook for business investment. But there is little doubt it will influence the timing of the Bank of England's first interest rate hike in nearly a decade and how sterling trades this year.
The Federal Reserve's planned smooth and gradual rate hike path may be bumpier than anticipated if U.S. economic growth over the next several months and punishingly cold winter weather follow a well-established recent pattern.
If emerging markets are to lead global economic performance one again as they did in recent years, an important foundation will be to convince as many people as possible that reported growth data are as accurate as they can possibly be.
Market forecasts for Brazil's economic growth this year have been falling steadily for months, reaching a meager 0.5 percent in Reuters latest quarterly poll published on Thursday. One year ago, a similar survey predicted growth of 2.5 percent in 2015.
At the beginning of 2014, many people were optimistic about the world economy. For the fifth straight year, it had seemed safe to declare the lingering effects of the 2008 financial crisis over and done with. This time is different: 2015 is likely to begin in a merited atmosphere of gloom.