Minsky's unusual system dynamics features

Minsky differs from conventional system dynamics models in various ways:

• Most programs store their mathematical formulas within a text block, which must be opened to see its equation. The mathematics of a Minsky model is shown explicitly on the design canvas;
• Most programs require every entity used to build an equation to be wired to the block in which the equation is defined, while each entity is shown only once on the design canvas. This generates the familiar system dynamics ``spaghetti diagram'', as even practitioners—rather than merely critics—often describe their models. Minsky enables entities to be shown multiple times on the design canvas, which substantially reduces the number of wires needed to build a model. Minsky's equations therefore resemble small ``spider webs'', rather than large bowls of spaghetti. This makes it easier to understand what a model does; and
• Most programs show the end results of a simulation. Minsky shows simulations dynamically, and the numerical values of parameters and variables are shown on the parameters and variables themselves. Parameters can be altered during a simulation, which enables them to be used as a ``control panel'' for simulation of policy proposals, etc.

These unusual features are best illustrated by building a simple model in Minsky. The next section explains how to build a simpler version of the predator-prey model.