The two outcomes above appear the most likely. But we are in uncharted territory in many ways, and it is possible that the world may not work the way standard Keynesian economic models suggest it will.
In those models, for example, inflation can become a problem only when the economy is overheating. But what if the unconventional tools that central banks have used over the last half a decade have different results, causing, for example, a spike in prices even as the economy remains depressed? Then you could see bonds fall in value, but unlike in the "good" scenario above, not be accompanied by a rising economic tide.
Or, perhaps the large deficits that the United States and other countries have run during the crisis years will one day cause a crisis of confidence in advanced nations' debt. Interest rates could spike (and bonds could fall sharply in value, and probably other investments, too) not because the economy is recovering, but because of that loss of market confidence.
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Or maybe some external force will result in an economic downturn, which world economic policy makers would have few tools to fight after exhausting most of them over the last few years. If that happened, what would in normal times cause a mild downturn might instead bring about something more dangerous, like a new depression and market collapse.
Which of these is most likely? For the last few years, many official projections — forecasts from government agencies and bank economic research shops, for example — have tended toward the "good" outcome, predicting a full-throated expansion as being just around the corner. Many commentators, particularly on cable financial television, have predicted an "ugly" one, full of out-of-control inflation, debt crises and collapse.
But the pattern of the last few years shows that the "bad" scenario has been closest to the reality. That doesn't mean the rest of the bad script will continue in the years ahead, but it should prompt those predicting the first or third outcome to wrestle with why they have been wrong so far.
—By Neil Irwin, The New York Times