The article compares two ways to help the economy during tough times when interest rates are stuck at zero: using a fixed exchange rate or targeting a specific price level. The researchers looked at data from Japan, the US, and the euro area, as well as a simplified model. Both methods can boost inflation expectations when people trust the government's promises. But if people don't fully trust the government, price-level targeting might not work as well because it's harder to see if the government is sticking to its plan.