The article "Mapping the Tariff Waters" looks at how different countries set tariffs on imports. By studying data from 120 countries, the researchers found that tariffs often protect labor-intensive industries more than traditional industries. They also discovered that the distinction between developed and developing countries is important in understanding tariff policies, but not the only factor. Overall, countries tend to protect certain sectors more than others, and this protection is influenced by regional and socio-economic factors.