London (CNN Business) - There's a reason economics is frequently called the "dismal science."
What's happening: The US economy is on track for a boom, with the Federal Reserve predicting last week that it would expand by 6.5% this year. That would mark the fastest growth since 1984, when Ronald Reagan was serving his first term as president.
But a survey of the country's top economists published by the National Association for Business Economics on Monday shows that many in the field are still worried about what could be coming down the pike.
See here: A majority of the 205 members surveyed said they believe risks to inflation are greater than those seen in the past two decades.
Inflation concerns have been in the spotlight thanks to anxiety on Wall Street. Investors, fearful that a rush to eat out at restaurants and hop on planes later this year could trigger a spike in prices, have sold US government bonds in recent weeks. Inflation, not coronavirus, is now the top risk cited by portfolio managers recently polled by Bank of America.
The big worry is that a burst of inflation could force the Fed to raise interest rates or taper bond purchases sooner than expected in order to cool off the economy. Almost half of NABE respondents think the central bank could roll back some stimulus measures by the end of 2022, while 40% don't think that will happen until at least 2023.
That's not all: More than 40% of economists surveyed said they think stimulus measures passed by the US government have been "about right." But they're also keeping an eye on elevated levels of borrowing. If rates were to suddenly rise, the cost of making interest payments on piles of debt could become increasingly burdensome.
Most respondents said they were "concerned about the trajectory of public debt." Only 12% said they weren't scared at all, while 37% said they were mildly concerned, 26% said they were concerned and 25% were very concerned.
Almost two-thirds of respondents think the fiscal deficit should be addressed by enacting policies that spur stronger economic growth. Meanwhile, more than one-third favor exercising greater spending discipline or increasing taxes.
Not everyone is nervous about additional spending, though. Per NABE, 38% of those polled think infrastructure investment should be a top priority as the Biden administration puts together its next piece of legislation.
The backdrop: More than 13% of the US population is now fully vaccinated against Covid-19, and AstraZeneca(AZN) said Monday that its vaccine showed 79% efficacy against symptomatic disease in a new US-based clinical trial. The vaccine was well tolerated and no safety concerns were identified, the company said.
The findings will be submitted to regulators as part of an application for emergency use in the United States, adding even more fuel to the country's vaccination efforts.