Revenue Watch Institute, which has headquarters in New York, published its governance index Wednesday, measuring transparency and accountability of 58 countries. The countries listed in the index produce 90 percent of the diamonds, 85 percent of the oil and 80 percent of the copper in the world.
The report said 47 of the 58 countries investigated scored below the "satisfactory" rank of 70. Norway was listed as the highest performing country with a 98, with 100 being the top score. Myanmar ranked worst with a score of 4.
In terms of companies, Norway's Statoil, Mexico's Pemex and Brazil's Petrobras received top scores, while national companies in Myanmar and Turkmenistan ranked near the bottom.
Revenue Watch said it aims to shed light on the so-called resource curse, in which developing countries may use natural resources to prop up corrupt regimes.
"The index research reveals a governance deficit in how transparent and accountable countries are with their natural resources," Revenue Watch President Daniel Kaufmann said in a statement.
Revenue Watch examined governance, legal frameworks, transparency levels, as well as checks and balances, and said every country has room for improvement.