The study looked at different ways the central bank can control the economy when interest rates are low. They used a model based on the euro area to see which strategy works best. They found that targeting the price level is the most effective way to stabilize inflation and output, and reduce the chances of hitting the lower limit on interest rates. Temporary price level targeting also helps, but not as much as permanent price level targeting. Looking at past inflation rates and targeting an average also works well. The key is for the central bank to commit to keeping interest rates low for a long time.