Some people would argue that 2016 was the year that the world economy started to come apart, with the passage of Brexit and the election of Donald Trump. Whether or not the “coming apart” process started in 2016, in my opinion we are going to see many more steps in this direction in 2017. Let me explain a few of the things I see.
 Many economies have collapsed in the past. The world economy is very close to the turning point where collapse starts in earnest.
The history of previous civilizations rising and eventually collapsing is well documented.(See, for example, Secular Cycles.)
To start a new cycle, a group of people would find a new way of doing things that allowed more food and energy production (for instance, they might add irrigation, or cut down trees for more land for agriculture). For a while, the economy would expand, but eventually a mismatch would arise between resources and population. Either resources would fall too low (perhaps because of erosion or salt deposits in the soil), or population would rise too high relative to resources, or both.
Even as resources per capita began falling, economies would continue to have overhead expenses, such as the need to pay high-level officials and to fund armies. These overhead costs could not easily be reduced, and might, in fact, grow as the government attempted to work around problems. Collapse occurred because, as resources per capita fell (for example, farms shrank in size), the earnings of workers tended to fall. At the same time, the need for taxes to cover what I am calling overhead expenses tended to grow. Tax rates became too high for workers to earn an adequate living, net of taxes. In some cases, workers succumbed to epidemics because of poor diets. Or governments would collapse, from lack of adequate tax revenue to support them.
Our current economy seems to be following a similar pattern. We first used fossil fuels to allow the population to expand, starting about 1800. Things went fairly well until the 1970s, when oil prices started to spike. Several workarounds (globalization, lower interest rates, and more use of debt) allowed the economy to continue to grow. The period since 1970 might be considered a period of “stagflation.” Now the world economy is growing especially slowly. At the same time, we find ourselves with “overhead” that continues to grow (for example, payments to retirees, and repayment of debt with interest). The pattern of past civilizations suggests that our civilization could also collapse.
Historically, economies have taken many years to collapse; I show a range of 20 to 50 years in Figure 1. We really don’t know if collapse would take that long now. Today, we are dependent on an international financial system, an international trade system, electricity, and the availability of oil to make our vehicles operate. It would seem as if this time collapse could come much more quickly.