The data displays the Herfindahl-Hirschman Index (HHI) on the health insurance market in the Netherlands from 2013 to 2017, by province. In 2017, the province of Zuid-Holland reached an HHI of 1,800. The Herfindahl-Hirschman Index (HHI) measures the market concentration and derives from micro-economics. According to the source, a high number means a higher concentration, less players on the market and a higher market share. The source also assumes that lower concentration means more competition between insurance companies and more choice for consumers.
