The wealth of the nation is the sum of the products and services provided by all the citizens in that nation. The wealth of the citizen is how much he/she can take from this sum. Wealth can be thought of the same way as energy, as it is a motivator for action. Just like energy, wealth must flow. Just like energy, the flow of wealth can tie itself into knots, and as people get used to this, the existence of those things covered by this flow of wealth is dependent upon the perpetuation of the flow of which it is a constituent. All things tend entropically, which means eventually either the flow will break, or a constituent will collapse, in 100% of the cases. If this is our only measure of wealth, it will only get more difficult to manage in the future.
Shouldn't personal wealth also be considered as the lack of dependence upon the sum of the nations wealth? I.e. a man's personal wealth is inversely proportional to the amount of resources he takes from the nation's pool of wealth. How could this be usefully measured?