The Moscow metropolitan area is the largest metropolitan area in Europe and one of the largest in the world, with a population of over 16 million people. Moscow makes up the core of the area, contributing almost 12 million people to its population. The remaining four million live in the cities surrounding Moscow, including Khimki, Shchyolkovo, Balashikha and Elektrostal. The Moscow metropolitan region has some of the highest rates of development in Russia and makes up roughly 15% of the country's economy. The Gross Regional Product of Moscow is $340 billion.