G. P. Richardson July 20061Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyDynamic Complexity50th Annual Meeting of the International Society for the Systems SciencesGeorge P. Richardson Rockefeller College of Public Affairs and Policy University at Albany, SUNYG. P. Richardson July 20062Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyDecisionsReal WorldInformation FeedbackStrategy, Structure, Decision RulesMental ModelsVirtual WorldSelected Missing Delayed Biased AmbiguousImplementation Game playing Inconsistency Short termUnknown structure Dynamic complexity Time Delays Impossible experimentsMisperceptions Unscientific Biases DefensivenessKnown structure Variable Complexity Controlled ExperimentsLearning in and about Complex Systems Sterman (1994)Inability to infer dynamics from mental modelsG. P. Richardson July 20063Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyDynamic 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 tradeoffsG. P. Richardson July 20064Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanySystem Dynamics ContributionsThinking dynamicallyMove 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 processesCompensating feedback structures and policy resistanceCommunicating complex nonlinear system structureThinking in stocks and flowsAccumulations are the resources and the pressures on policyPolicies influence flows Modeling and simulationAccumulating (and remembering) complexityRigorous (daunting) model evaluation processes Controlled experimentsReflectionG. P. Richardson July 20065Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyThe system dynamics modeling processAdapted from Saeed 1992G. P. Richardson July 20066Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyProcesses focusing on system structureG. P. Richardson July 20067Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyProcesses focusing on system behaviorG. P. Richardson July 20068Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyTwo kinds of validating processesG. P. Richardson July 20069Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanySix Traditions Contributing to the Evolution of Feedback Thought Biology: math models Econometrics Engineering Social Sciences Biology: homeostasis LogicTwo Threads of Feedback Thought System dynamics arises in the servomechanisms thread (the first four in this list)G. P. Richardson July 200610Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyForresters 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 discrepancyG. P. Richardson July 200611Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyThe 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.G. P. Richardson July 200612Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyDynamicsG. P. Richardson July 200613Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyNew York City Population, 1900-2000G. P. Richardson July 200614Rockefeller College of Public Affairs and PolicyRockefeller College of Public Affairs and Policy University at AlbanyUniversity at AlbanyGlobal Atmospheric Methane (1860-1994)G. P. Richardson J