Vaults full of research attest to how emerging-market optimism is more soundly based than rich-country pessimism. People around the world are living longer, healthier lives; fewer fall victim to war and famine; as education spreads, discrimination and prejudice are waning. Similarly, the summers were rarely as idyllic or the nation as glorious as sentiment would have it.
But to reject pessimism and nostalgia as simply inaccurate misses the point. They are powerful forces that are shaping politics. To harness them, you must first understand them.
Nostalgia serves optimists and pessimists alike as an anchor in a world being transformed. New technologies, including artificial intelligence, threaten to disrupt entire industries and to alter the relationship between the state and the citizen. After two centuries power is shifting from the West back to China. The planet is ageing faster than at any time in history. Its climate is changing. It is ever more racially and culturally mixed.
At such moments, people are drawn to nostalgia as a source of reassurance and self-esteem. Many Brexiteers hope that leaving the European Union means they will once again belong to a dynamic “global Britain”. Catalans evoke an idealised past in pursuit of a distinctive identity. Alarmed by corruption and recession, Brazilians have elected a president who harks back to the certainties of a military dictatorship they rid themselves of three decades ago. When Mr Trump boosts coal and steel, men who feared that they had been marginalised in dirty, dying industries suddenly feel as if they are worth something again.
In the rich world, nostalgia also offers a way to rebel against someone else’s idea of progress—to “take back control”. The farright Alternative for Germany has its strongest support in the former East, where voters regret their loss of community and security. In France the gilets jaunes smash shop windows on the Champs-Elysées because they cannot make ends meet. They reject the trade-off offered by their president, Emmanuel Macron, between national prosperity and individual economic security.