Why are so many key global leaders pursuing so many stupid economic policies?

As recently as January 2018, the International Monetary Fund issued one of its most upbeat economic forecasts in recent years, extolling “broad based” growth, with “notable upside surprises.”

By last month, the fund had sliced its forecast for expansion this year to 3.2 percent — a significant falloff from the 3.9 percent projection reiterated just six months earlier — and had pronounced the economic picture “sluggish.” American investors are more concerned; the bond market is sounding its loudest recessionary alarm since April 2007.

The deterioration in the economic picture is not the consequence of irresponsible behavior by banks or a natural disaster or an unanticipated economic shock; it’s completely self-inflicted by major world leaders who have delivered almost universally poor economic stewardship.

The trade war initiated by President Trump sits firmly atop the list of bad policies. But Brexit has tipped Britain into economic contraction. With European governments unwilling to pursue structural reforms, the continent is barely growing. President Xi Jinping of China has focused on standing up to Mr. Trump and solidifying his own power. After a promising start reforming the economy, India’s prime minister, Narendra Modi, has turned instead to oppressing his country’s Muslim minority.