The Economy Is Stronger. These 4 Things Will Determine What Happens Next

The U.S. economy grew at a strong pace in the spring as the country emerged from the darkest days of the coronavirus pandemic. The question now is what happens next, especially as the delta variant continues to spread.

On Thursday morning, the Commerce Department reported gross domestic product grew 6.5% in the period between April and June from a year earlier as the rollout of vaccines spurred a surge in economic activity.

Although that was below forecasts of around 8% growth, it still marked the second-strongest period of growth since...