The article explores whether joining a regional trade group makes a country more or less protective of its trade. The researchers looked at how being in these groups affects a country's trade policies. They found that countries in these regional trade arrangements tend to lower their tariffs and barriers to imported goods from within the group while sometimes raising barriers to imports from outside the group. In simple terms, being part of a regional trade bloc can lead countries to be more open to trade with each other but more protective against trade from countries outside the bloc.