With China lowering its peg to the U.S. dollar by 3.5 percent in the last few days, it's timely to consider the former president's thoughts on the topic. Here are some relevant bits from our conversations:

I asked former President Carter in 2010 if the U.S. could force China to appreciate its currency.

"No. And the more we antagonize China, the more it will drag its feet," Carter said. " I normalized diplomatic relations with China [in 1979]. They are gradualists and can't be coerced into doing what America wants. Plus, we have imbalances with several countries — not just China — and we're not going to ask all of them for a correction. I applaud President Obama for not ceding to populist demands in the House calling for China to appreciate its currency."

Read MoreCramer: Why China had to devalue the yuan

American consumers are over-leveraged and support China by buying their cheap exports. So, if we can't force China to appreciate its currency, is there something we can do to curb our own spending and get America to deleverage?

"During my presidency, I tried to make the case that Americans should be conservative in their spending," Carter said. "I made a speech to the nation saying that we must cut back. This meant conserving fuel and being economically prudent. The country was going through a tough time economically during my presidency, and Ronald Reagan campaigned against me promising to return America to be a shining city on a hill."

Carter said Americans have started to deleverage to a degree since the 2008 financial crisis but perhaps not as quickly or as much is necessary.

"I think President Obama should make it clear to Americans that we need to get back to American virtues of thrift and frugality," Carter said. "The president has the largest megaphone and he's not talking about these issues. But then again, it's not popular to tell Americans to be better about how they spend their money."

Carter said he doesn't think there is much that President Obama can do to accelerate U.S. economic growth.

"When it comes to the economy, there is so much that's out of the President's control — like China devaluing its currency. By the time an economic decision reaches the president, so much has already been decided such as monetary and labor policies."

Read MoreAre red or blue states better job creators?