The documentation provides a detailed section, providing information on how Welfare index is determined...
"1. The Welfare Index [ top ]
The welfare index is one of the most influential indexes in Simcountry.
The welfare index has a major influence on the corporate welfare index. The corporate welfare index is directly responsible for the productivity in corporations.
The welfare index in each country is composed of several other indexes and is used in many game functions as an indicator of the general situation in the country.
The happier the population in the country is, and the better the economy is doing, the higher is the welfare index.
The index can fluctuate between 90 (and in some cases even lower), and 140.
The Welfare Index is taking the lowest value of several other indexes:
The Health Index
The Education Index
The Transportation Index
The Supply Index