I am not sure what you (ATinNM) are saying (in general) about modeling an 'economy': that it is impossible, too expensive, or something else?

Economies are modeled - they have to be modeled in some way, for governance. That is why there are national budgets, and offices of budget and management. Now, these models may be imprecise, contentious or too narrow, but they are used to predict the effect of changes in the rules of different types of transactions of citizens, companies, organizations, government and 'external transactions' (i.e. how these rules might interact with the rules of other budget systems in other nations).

However 'inaccurate' such national budgets may be, it is correct to say that building a parallel one would an expensive project. However, the Dutch government is already considering the use of XBRL to 'code' their national budget in such a way as to allow any citizen to play 'what if' with it. The mandated use of XBRL would also bring transparency to corporate accounting, because the tax authorities could also play 'what if' with those accounts. Stress testing, I suppose you'd call it ;-)

An explanation of XBRL is here. There's an XBRL conference in Paris 23-25 June.

So there may be a 'game' to be played in the future that does not require the building of the model.

TBG's 'game', as I understand it, is not about producing a perfect, but coarse, real 'what if' modeled budget, but a simulation of the budget decision processes so that citizens can better understand the processes and thus vote in a more informed manner. Lemonade Stand 3.0.

BTW I wrote a diary about XBRL a year ago, and the different views expressed in comments are useful to the present discussion.

You can't be me, I'm taken