The next decade is likely to be a period of growing instability in the United States and western Europe, which could undermine the sort of scientific progress you describe in the Opinion collection of '2020 visions' (Nature 463, 26–32; 2010).

Quantitative historical analysis reveals that complex human societies are affected by recurrent — and predictable — waves of political instability (P. Turchin and S. A. Nefedov Secular Cycles Princeton Univ. Press; 2009). In the United States, we have stagnating or declining real wages, a growing gap between rich and poor, overproduction of young graduates with advanced degrees, and exploding public debt. These seemingly disparate social indicators are actually related to each other dynamically. They all experienced turning points during the 1970s. Historically, such developments have served as leading indicators of looming political instability.

Very long 'secular cycles' interact with shorter-term processes. In the United States, 50-year instability spikes occurred around 1870, 1920 and 1970, so another could be due around 2020. We are also entering a dip in the so-called Kondratiev wave, which traces 40-60-year economic-growth cycles. This could mean that future recessions will be severe. In addition, the next decade will see a rapid growth in the number of people in their twenties, like the youth bulge that accompanied the turbulence of the 1960s and 1970s. All these cycles look set to peak in the years around 2020.

Records show that societies can avert disaster. We need to find ways to ameliorate the negative effects of globalization on people's well-being. Economic inequality, accompanied by burgeoning public debt, can be addressed by making tax rates more progressive. And we should not expand our system of higher education beyond the ability of the economy to absorb university graduates. An excess of young people with advanced degrees has been one of the chief causes of instability in the past.

Author information Affiliations Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, 06269, Connecticut, USA Peter Turchin Authors Peter Turchin View author publications You can also search for this author in PubMed Google Scholar

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