The FDI Regulatory Restrictiveness Index is a tool that measures the restrictiveness of a country's foreign direct investment (FDI) policies and regulations. The index is produced by the Organisation for Economic Co-operation and Development (OECD) and is designed to provide investors with information about the regulatory environment in different countries.

The importance of the FDI Regulatory Restrictiveness Index lies in its ability to help investors identify the countries that have the most favorable policies and regulations for FDI. Countries that rank high on the index are typically seen as more attractive destinations for foreign investment, as they have fewer barriers to entry and more supportive policies for foreign investors.

The index can also have an impact on a country's competitiveness rank, as it is becoming increasingly important for countries to attract foreign investment in order to remain competitive in the global economy. Countries that rank low on the index may face challenges in attracting foreign investment, as investors may perceive them as having a less supportive regulatory environment.

Overall, the FDI Regulatory Restrictiveness Index is an important tool for investors and policymakers who are interested in foreign investment. It provides a comprehensive picture of a country's FDI policies and regulations, and can help investors make informed decisions about where to invest their capital. It can also provide valuable insights for policymakers who are looking to attract foreign investment and improve their country's competitiveness in the global economy.