Download site for CDF reader program
Here is a new Wolfram CDF, which I have constructed based on a macro model. The assumptions behind the model–other than the exact parameter values–are loosely stated in this list:
1) industries dominated by a handful of firms, rather than perfect competition
2) production technology that requires capital and labor inputs
3) chronic underemployment and less-than-full capacity utilization (percent of capital stock in use at a given time)
4) sovereign money and a policy-determined interest rate
5) two groups of households, only one of which has money to save
6) net investment a function of the profit and capacity utilization rates
7) budget deficits offset by the issuance of treasury bills and sovereign money
8) a government that employs workers to produce free public services
9) a fiscal policy rule with (a) a balanced budget target (labeled “0” in the CDF above) or (b) public production and capacity utilization targets (labeled “1” in the CDF above)
10) nonlinear functions that result in endogenous cycles in this figure for some parameter values and policy functions (try different parameter values with policy rule “1” for example)
11) gradual adjustment of public and private-sector output toward levels indicated by one of the two fiscal policy rules and output demand, respectively.
The arrows in the CDF show directions of movement in 2D space, where the two axes represent public production (horizontal) and capacity utilization (vertical). We got a different look at the same model in this previous post. In this new CDF, I have tried to improve on the realism of the parameter values. Here is a link to the download site at Wolfram for the needed CDFPlayer software.
The most serious omissions in the model above, by the way, are a foreign sector, a mechanism by which the broad price level can change over time, and commercial bank deposits and loans. As mentioned before, I am working on adding these and other new features to a larger version of the model depicted above for the upcoming International Post Keynesian Conference in Kansas City later this month. Any macroeconomic model, of course, is only an abstract and simplified version of a real economy. But the bottom line is that (1) guiding fiscal policy with a balanced-budget target leads to instability in all cases, while (2) the output-stabilizing fiscal rule generates a business cycle of varying size or convergence to a point.