The Human Development Index, or HDI, is a real-world statistic used by the United Nations to measure the level of "human development" in countries. The statistic - a number from 0 to 1 - takes elements of data from the area's life expectancy, education levels, and per-capita Gross National Income (GNI). From this number, an area can be categorized as developed (high development), developing (middle development), or underdeveloped (low development).
HDI in Fate of the World
When the game starts, each world region will have its own unique HDI figure, based on real world data and predictions. For example, North America starts with a high HDI while North Africa has a very low HDI. Other nations, like Russia or China, fall somewhere in between. In addition to regional HDIs, there is also a global HDI based on the average HDI of every person on Earth. Starting on 2020, GEO's decisions will both directly and indirectly influence the HDIs of regions.
In most games, the gap in HDIs between rich and poor nations will grow smaller, as developed regions are hit by austerity measures and resource shortages while underdeveloped regions experience gains in healthcare and education.
How does HDI impact gameplay?
Many missions specify a given HDI range that you need to win or at least not lose. In Fuel Crisis and Three Degrees, the GEO will fail in its mandate if the global HDI drops below 0.5 (most commonly due to global famine and civil war), heralding a new dark age. A high HDI also increases the speed at which research in a region will be completed.