Subject: managing innovation using stock and flow diagram

Posted by Niall Palfreyman on 1/30/2009
In Reply To:managing innovation using stock and flow diagram Posted by George Richardson on 1/30/2009

Message:

Just a quick note: I assume George has made a slip here, and actually meant the logistic equation:

X(t+1) = a * X(t) * (1 - X(t))

You can explore this in Stella by creating the following:
Stock: X
Biflow into X: births
Converter linked to births: a
Set births = "a * X * (1-X) - X"
Set DT = 1.
Then play with values of a as George says. The transition to chaos comes at around a=3.7. What I don't quite understand at the moment is that my model freaks out when a>=4.

The conditions for continuous chaos that I give my students are that you need 3 stocks not directly linked by flows, and at least one of the flows must be nonlinear.

Best wishes,
Niall Palfreyman.