The price of a barrel of oil has fallen by more than a third since the middle of last year, to about $77 from $121, below its prewar level, as markets adjusted to Western embargoes of Russian supply and as oil was released from emergency reserves. Some economists warned a reopening Chinese economy would push oil prices higher, but that hasn’t happened yet.
In Europe, benchmark wholesale natural-gas prices have slumped by almost 90% since last sum...