As former and current U.S. economists gathered at the annual American Economics Association conference this past week, a varying degree of opinions were offered on the health and state of the U.S. economy.

Reuters reported on Jan. 3 that comments made by Boston Federal Reserve President Eric Rosengren and former U.S. Treasury Secretary Lawrence Summers offered caution with the U.S. economy as the Federal Reserve Bank is looking at raising interest rates mid 2015.

Rosengren repeated his call for the U.S. central bank to take its time in establishing more normal policy after years of stimulus to boost the economy.

“I believe the continued very low core inflation and wage growth numbers provide ample justification for patience,” Rosengren said. “A patient approach to policy is prudent until we can more confidently expect that inflation will return to the Fed’s 2 percent target over the next several years.”

Summers, a Harvard economics professor, reiterated to Reuters how he is unsatisfied with the progress of the U.S. economy.

“The United States is now about 10 percent below potential, as it was estimated in 2007,” Summers said. “In so far as the output gap has closed, it is not because we have gotten closer to what we thought potential was. It is because we have revised downwards our assessment of the economy’s potential. That 10 percent potential represents about $20,000 per American family.”

Reuters reported that the comments of Rosengren and Summers come as Fed chair Janet Yellen lays the groundwork for the Fed’s first interest rate hike in nearly a decade. The Fed changed its interest rate guidance last month at its policy setting meeting, adding language in its statement that the central bank is moving closer to raising rates.

Summers says the U.S.’ next economic booster could be exporting its fossil fuels around the globe, a move that could make America the next Saudi Arabia, and reduce American gasoline prices.