NEW YORK (TheStreet) -- President-elect Donald Trump selected former Goldman Sachs (GS) - Get Report partner Steven Mnuchin as the Treasury Secretary and billionaire investor Wilbur Ross as Commerce Secretary on Wednesday.

"These new appointees have to move very quickly on detailed design and then talk about implementation with the politicians," Allianz Chief Economic Advisor Mohamed El-Erian told CNBC's Rick Santelli Wednesday morning.

Mnuchin told CNBC this morning that he expects interest rates to remain low for the next couple of years.

"He's right," El-Erian said. "Interest rates will be lower than they have been in the past, but they will be going up as the market prices in higher growth and high inflation."

El-Erian argued for the appointees to be judged by their actions and expertise. "Both gentlemen bring to the table an understanding of markets and how the private sector functions."

Now, they must complement that expertise with people who understand the complexities of policymaking.

"Remember, good policy gets made at the intersection of the economy, markets and politics. That is where they are going to have to function," El-Erian said.