[[System structure is the source of system behavior]] Problems with behavior-based economic models - overemphasis on flows and underemphasis on stocks - statistical links between flow are nonexistent -- flow varies in response to stocks not to other flows That's why behavior-based econometric models are pretty good at predicting the *near-term* performance of the economy, quite bad at predicting the *longer-term* performance, and terrible at telling one how to improve the performance of the economy.