dynamic complexity
Download
Skip this Video
Download Presentation
Dynamic Complexity

Loading in 2 Seconds...

play fullscreen
1 / 63

dynamic complexity - PowerPoint PPT Presentation


  • 157 Views
  • Uploaded on

Dynamic Complexity. 50th Annual Meeting of the International Society for the Systems Sciences George P. Richardson Rockefeller College of Public Affairs and Policy University at Albany, SUNY. Learning in and about Complex Systems Sterman (1994). Unknown structure Dynamic complexity

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'dynamic complexity' - oshin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
dynamic complexity

Dynamic Complexity

50th Annual Meeting of the

International Society for the Systems Sciences

George P. Richardson

Rockefeller College of Public Affairs and Policy

University at Albany, SUNY

slide2

Learning in and about Complex Systems

Sterman (1994)

Unknown structure

Dynamic complexity

Time Delays

Impossible experiments

Real World

Virtual World

Known structure

Variable Complexity

Controlled Experiments

Selected

Missing

Delayed

Biased

Ambiguous

Implementation

Game playing

Inconsistency

Short term

Information Feedback

Decisions

Misperceptions

Unscientific

Biases

Defensiveness

Strategy, Structure, Decision Rules

Mental Models

Inability to infer dynamics from mental models

dynamic complexity arises because systems are
Changing over time

Tightly coupled

Governed by feedback

Nonlinear: changing dominant structure

History-dependent

Self-organizing

Adaptive

Counterintuitive

Policy resistant

Characterized by tradeoffs

Dynamic Complexity arises because systems are…
system dynamics contributions
Thinking dynamically

Move from events and decisions to patterns of continuous behavior over time and policy structure

Thinking in circular causal / feedback patterns

Self-reinforcing and self-balancing processes

Compensating feedback structures and policy resistance

Communicating complex nonlinear system structure

Thinking in stocks and flows

Accumulations are the resources and the pressures on policy

Policies influence flows

Modeling and simulation

Accumulating (and remembering) complexity

Rigorous (daunting) model evaluation processes

Controlled experiments

Reflection

System Dynamics Contributions
slide9

Six Traditions Contributing to the Evolution of Feedback Thought

  • Biology: math models
  • Econometrics
  • Engineering
  • Social Sciences
  • Biology: homeostasis
  • Logic
  • Two Threads of Feedback Thought
  • System dynamics arises in theservomechanisms thread
  • (the first four in this list)
forrester s hierarchy of system structure
Forrester’s Hierarchy of System Structure
  • Closed boundary around the system
  • Feedback loops as the basic structural elements within the boundary
  • Level [stock] variables representing accumulations within the feedback loops
  • Rate [flow] variables representing activity within the feedback loops
    • Goal
    • Observed condition
    • Detection of discrepancy
    • Action based on discrepancy
the endogenous point of view
The Endogenous Point of View
  • The closed causal boundary takes top billing
  • Dynamics arise from interactions within that boundary
  • Systems thinking is the mental effort to uncover endogenous sources of system behavior.
challenging the clouds in a study of leasing in the automobile industry

?

‘Challenging the clouds’ in a study of leasing in the automobile industry

“We’re not in the used car business!”

slide22

But although the stock-and-flow insight holds, global climate is of course much more complex than that.

And still much more complex than this simple global climate model, as well!

feedback thinking

Feedback Thinking

“For one good deed leads to another good deed, and one transgression leads to another transgression.” (Pirke Avot)

a classic reinforcing loop myrdal 1944 merton 1948
A Classic Reinforcing Loop(Myrdal 1944, Merton 1948)

Prejudice against the minority group

Majority’s perception of the inferiority of the minority

Economic and educational discrimination against the minority

(R)

Achievements of the minority group

structure and dynamics of terrorist cells
Structure and Dynamics of Terrorist Cells

(R)

Interfering with terrorist funding

Terrorist funding

Peripheral support for terrorists

(B)

Efforts to suppress terrorists

(R)

Terrorist actions

(B)

(B)

(R)

Recruiting terrorists

Terrorist group

Losing terrorists

(R)

(B)

Terrorist zeal

(R)

(R)

Terrorist martyrs to the cause

slide30

Insights about building teamwork in a public school

Teamwork and Communication are self-reinforcing

the problem 1996 u s welfare reform
The Problem: 1996 U.S. welfare reform
  • Since 1930, a guarantee of lifetime Federal support
  • 1996 legislation ended that:
    • Temporary Assistance for Needy Families - TANF
    • At most five years of Federal support in one’s lifetime
  • The clock started for everyone on TANF in 1997
  • People began timing out in 2002
  • Financial burden will begin shifting to the states and counties
  • A series of facilitated group modeling efforts in three New York State counties tried to help counties cope. Where are the leverage points?
three policy mixes
Three Policy Mixes
  • Base run (for comparison)
    • Flat unemployment rate
    • Historical client behaviors
  • Investments in the “Middle”
    • Additional services to TANF families
    • Increased TANF assessment & monitoring
    • Safety net assessment & job services
  • Investments on the “Edges”
    • Prevention
    • Child support enforcement
    • Self-sufficiency promotion
base edges and middle compared populations on the welfare rolls
Base, “Edges,” and “Middle” Compared:Populations on the Welfare Rolls

“Edges” looks better.

total job finding flows from tanf
Total Job-Finding Flows from TANF

“Middle” looks better.

program expenditures
Program Expenditures

“Edges” looks worse, then better.

populations in the welfare system
Populations in the Welfare System

“Middle” looks worse than “Base”! “Edges” looks much better.

total recidivism flows back to tanf
Total Recidivism Flows (back to TANF)

The hint for understanding the puzzling dynamics: recidivism.

slide48

Behavior of the Archetype in response

to increased TANF support capacity

Total families at risk

Families on TANF

Post-TANF employed

the behavior of the archetype
The Behavior of the Archetype
  • Families on TANF initially declines, as more support hastens job finding.
  • Post-TANF families employed initially increases, just as policy makers would predict.
  • Eventually (it takes a year and a half to begin to see it), …
    • Families on TANF rises higher to a new high,
    • Post-TANF Employed declines to a new low,
    • And Total Families at Risk rises!
  • …All because of increased TANF support capacity!
slide50

Why?

  • Increasing TANF support
  • Speeds job finding,
  • Swamping downstream Post-TANF jobs and support
misattribution
Misattribution?
  • Desirable rise in Post-TANF employed continues for almost a year and half after the intervention
  • Families on TANF falls below initial for over a year after increasing TANF support capacity
  • Very hard (impossible?) to see that the rise in Total Families at Risk is attributable solelyto the improvement in TANF support capacity
  • Dynamics almost certainly to be blamed on a weakening economy, a rise in client pathologies, or other exogenous factors
slide52

A Loop View of the Archetype in Detail

Suppose TANF support capacity increases…

slide53

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

White bar (left) is the time slice of interest

Red arrows (below) are the dominant influences

slide54

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide55

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide56

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide57

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

White bar (left) is the time slice of interest

Red arrows (below) are the dominant influences

slide58

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide59

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide60

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide61

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

slide62

4,000

3,000

B: Employed load controls recidivism

2,000

1,000

0

0

30

60

90

120

Time (Month)

Dynamic complexity even in a structure this aggregate and tiny!

system dynamics and dynamic complexity
System Dynamics and Dynamic Complexity
  • Thinking dynamically moves us beyond separate events and decisions, toward understanding.
  • Feedback thinking extends traditional causal thinking.
  • It improves (makes more realistic) how we think about the world and how we think about changing it.
  • The endogenous point of view is empowering.
ad