From the World in the Modelto the Model in the WorldMary S. MorganLSE & University of AmsterdamBA “Modelling for Policy” C...
Modelling creates ‘small worlds’: the‘world in the model’A. Scientists represent our world into small modelsB. Those ‘smal...
The qualities of small worlds asworking objects for science?Models are representations that create  manageably small and m...
The qualities of small worlds asworking objects for science?Models are representations that create  manageably small and m...
Manipulable resources in models                          © M.S. Morgan, 2012
Using small worlds as technologiesof enquiryInto the world of the model and with the model  into the world the model repre...
Samuelson’smacro-economicsystem (1939)      © M.S. Morgan, 2012
Tinbergen’s economic model for theGreat Depression (1939)                           © M.S. Morgan, 2012
Newlyn-PhillipsHydraulicmacro-economicmodel (1949)Now in LondonScience Museum,computation gallery                      © M...
© M.S. Morgan, 2012
Technology of enquiryWorking with models = a form of experiment: with questions, model manipulations, answers.• Eg Samuels...
Experiments: seek valid inference,not correspondent truth, betweenmodel and world• Lab experiments – internal validity (wi...
So …..• Models may be truth-makers about the small  world in the model, but not of the world that the  model represents• R...
With sufficient usage, models slidefrom being a lens to view the worldinto those things seen in worldUsing small world acc...
‘Performativity’ of models followscognitive and imaginative shiftActing on, and with, small world models has  potential to...
Model-based actions don’t alwayswork in big world, because model• is a misleading/insufficient representation• is good at ...
Health Warnings 1 and 2:•   Model-based actions may be counter-    performative, even dangerous …think    seriously about ...
Thankyou        © M.S. Morgan, 2012
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From the World in the Model to the Model in the World

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British Academy "Modelling for Policy" presentation by Mary S. Morgan, LSE & Amsterdam

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From the World in the Model to the Model in the World

  1. 1. From the World in the Modelto the Model in the WorldMary S. MorganLSE & University of AmsterdamBA “Modelling for Policy” ConferenceMay 17-18th, 2012 © M.S. Morgan, 2012
  2. 2. Modelling creates ‘small worlds’: the‘world in the model’A. Scientists represent our world into small modelsB. Those ‘small worlds’ become autonomous working objects used as means of scientific enquiry• We enquire into the small world in the model to help us work through our theories and hunches.• We use the small model world to enquire with into the big world we live in to see if the models can help us understand that world, and intervene (policy) in useful ways. © M.S. Morgan, 2012
  3. 3. The qualities of small worlds asworking objects for science?Models are representations that create manageably small and manipulable worldsSmall does not necessarily mean simple, silly or simplistic but rather compressed or miniature worlds.• Think maps: not every detail given but exhibit relations we cannot grasp by eye.• Think poetry: spare, but dense, expressive prompts to imagination and understanding © M.S. Morgan, 2012
  4. 4. The qualities of small worlds asworking objects for science?Models are representations that create manageably small and manipulable worlds• Small does not necessarily mean simple, but rather compressed/miniature worlds.• Manipulability: a models needs resources that can be used as means of enquiry and to suggest modes of action © M.S. Morgan, 2012
  5. 5. Manipulable resources in models © M.S. Morgan, 2012
  6. 6. Using small worlds as technologiesof enquiryInto the world of the model and with the model into the world the model representsTechnology = a form of experiment:questions, model manipulations, and answers• Eg Samuelson’s algebraic model• Eg Tinbergen’s statistical model• Eg Newlyn-Phillips hydraulic model © M.S. Morgan, 2012
  7. 7. Samuelson’smacro-economicsystem (1939) © M.S. Morgan, 2012
  8. 8. Tinbergen’s economic model for theGreat Depression (1939) © M.S. Morgan, 2012
  9. 9. Newlyn-PhillipsHydraulicmacro-economicmodel (1949)Now in LondonScience Museum,computation gallery © M.S. Morgan, 2012
  10. 10. © M.S. Morgan, 2012
  11. 11. Technology of enquiryWorking with models = a form of experiment: with questions, model manipulations, answers.• Eg Samuelson: enquiry into world in model• Eg Tinbergen: enquiry with the model into the world• Eg Newlyn-Phillips Machine: enquiry into the world in the model and with the model into the world © M.S. Morgan, 2012
  12. 12. Experiments: seek valid inference,not correspondent truth, betweenmodel and world• Lab experiments – internal validity (within the lab) and external validity (beyond lab)• Model experiments – internal validity (in world of model) and parallel validity (in real world)• External and parallel validity both problematic and no easy solution to either!• Statistical ‘experiments’ – rules for statistically valid inference within and beyond the model, but may not be sufficient for action: eg demography © M.S. Morgan, 2012
  13. 13. So …..• Models may be truth-makers about the small world in the model, but not of the world that the model represents• Rather – learning about the world from working with models is best conceived as an inference problem ….• …. which invites modest claims about how much we can learn about the world from models, and• ...... scepticism about action in the world based on models, and the dangers of using models as “engines not cameras” (Donald Mackenzie, 2006) © M.S. Morgan, 2012
  14. 14. With sufficient usage, models slidefrom being a lens to view the worldinto those things seen in worldUsing small world accounts has imaginative and cognitive aspects that alter what we see and our ability to understand the world• Imaginative: think poetry, we see new things in the world because expressed in new ways• Cognitive: think tube map, and way we start to see world in terms of the map © M.S. Morgan, 2012
  15. 15. ‘Performativity’ of models followscognitive and imaginative shiftActing on, and with, small world models has potential to re-make the big world on the basis of the recipes found in the small worlds• Eg economic models and addiction (eg min. pricing for alcohol in Scotland)• Eg epidemiological models and vaccinations (eg Good-night Kiss model?)Sometimes this makes the big world behave more like the small world in the model, sometimes less! © M.S. Morgan, 2012
  16. 16. Model-based actions don’t alwayswork in big world, because model• is a misleading/insufficient representation• is good at description but does not give access to behavioural/causal structures• gives access to plausible explanations, but not to recipes that suggest means of action• its ceteris paribus conditions do not hold in world• suggests modes of action that are not consistent with other actions being taken• is not updated with feedback from rapidly changing situation in world ………………….. etc © M.S. Morgan, 2012
  17. 17. Health Warnings 1 and 2:• Model-based actions may be counter- performative, even dangerous …think seriously about using model to re/make the world• For the scientist, danger lies where there is no distinction between the world in the model and the model in the world © M.S. Morgan, 2012
  18. 18. Thankyou © M.S. Morgan, 2012

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