A lovely example here of how changing non-price factors can cause a change in the market supply of coffee beans used mainly for producing instant coffee.

Vietnam has over the years become of the world's largest growers, producers and exporters of coffee beans. So covid-related lockdowns which have hampered supplies of beans to the ports for international distribution will cause supply shortages and quickly flow through into higher prices for consumers.

Wholesale coffee prices have risen by 50% this year as supplies have been hit around the world. Retail prices tend to move in the same direction within a few weeks.

"'The lockdown of the South-Eastern city of Ho Chi Minh means Vietnam's exporters are struggling to transport goods, including coffee beans, to ports for shipment around the world."

Drought in Brazil is adding to supply worries.