Dutch national wealth is measured by the Gross domestic product (GDP). Economics and hard data. But the wealth of prosperity of a nation is more than only money; it is also related to more soft (subjective or emotional), less tangible data. Think of variables as: environment, health, social cohesion, fear, safety, innovation, good quality of life, education and equal opportunities.
What the indicators of this broader notion of prosperity are and how they can be measured is not clear yet.