This model shows the basic functioning and dynamics of a 'modern monetary system'.

The non-government sectors, consisting of the private and foreign sectors initial y starts with zero currency units. It is important to realize that  after creating a new currency the government must first spend currency units into the economy before they can be used: without currency units the private sector could not even pay taxes! A government that has its own freely floating currency can create a much money as it wants. It does not need tax receipts to finance its spending, and any money it spends into the economy above that collected in taxes represents income for the private sector. The model show that the government initially created 9 trillion money units, but spent only six trillion into the economy. The six trillion showed up as a government deficit, but also as wealth in the non-government sector.

Since the government can create as many money units as it wishes and transfer  them  to the private sector  to ensure an adequate level of demand in the in the economy,  austerity is unnecessary: money is available, though real resource may be scarce. This also shows that the government can contribute actively towards the creation of prosperity. 

Please note that this model was originally created by Gene Bellinger, IM 3206, from which this version was  cloned.

A Tragedy of the Commons situation exists whenever two or more activities, each, which in order to produce results, rely on a shared limited resource. Results for these activities continue to develop as long as their use of the limited resource doesn't exceed the resource limit. Once this limit is reached the results produced by each activity are limited to the level at which the resource is replenished. See also Archetypes.

An example of why it's so critical to understand where the boundaries are when considering a system. Go to Gene's version insight