Complex sentence: Some economists have thus classified countries on whether they adhere to common law or whether their legal system is based on French civil law, German civil law or Scandinavian civil law and done empirical research finding correlations between economic indicators and that classification.
Split into simpler sentences: Some economists have thus classified countries on whether they adhere to common law or whether their legal system is based on French civil law, German civil law or Scandinavian civil law. These economists have done empirical research finding correlations between economic indicators and that classification.