Model predictions and observation:

A  Cogni(vely  Realis(c  Model  of  Decision  Making  in  Ocean  Ecology    Philipp Koralus, Jens Koed Madsen, Ernesto Carrella, Richard Bailey

Introduction Simulating aggregate behaviours

Some future work

The erotetic theory of reasoning

Learning: Rather than conceptualising spots via catch-rate, we implement fishermen “folk ecology”, in a heat map-like updating system.

Communication and reliability updating: In the rare case of communication, fishers can learn from each other and update reliability given subsequent success/failure of the advice.

Policy-optimisation: Machine learning that may uncover optimal policy packages to stimulate desired behaviour.

University of Oxford

Select References

The  Erote)c  Theory  (Koralus  and  Mascarenhas  2013;  2016)  We  reason  through  upda)ng  a  mental  model  of  ques)ons  and  facts  

Key  idea:  we  try  to  take  successive  premises  as  strongest  possible  answers     -­‐   Our  ques)ons   tend   to  envisage   insufficient  alterna)ves,   leading  us   to   take  ques)ons  as   seKled    when  we  are  not  in  a  posi)on  to  seKle  them    -­‐  Predicted  new  systema)c  fallacies  (Koralus  &Mascarenhas  2016,  Mascarenhas  and  Koralus  2016).  -­‐  If  we  raise  enough  ques)ons  as  we  reason,  we  get  classical  soundness  and  completeness

Erote)c  theory  naturally  covers  decision-­‐making  (Koralus,  under  review)  

  -­‐   Use   opera)ons   from   Koralus   and  Mascarenhas   (2013;   2016),   but   input   decision   ques)ons   and    prac)cal  reasons.     -­‐   Can   model   both   successes   (classically   ra)onal   choice)   and   failures   (framing   effects,   choice    inconsistencies)  

The erotetic fisherDaily  ques)on  

Where  do  I  fish?  =  {xy1,  xy2,  …,  xyn}  Priori)es  sequen)ally  treated  as  answers    

Avoid  places  that  had  unacceptable  profit  in  past.  Somewhere  legal  for  me.  Somewhere  known  to  have  acceptable  profit  in  past.  Somewhere  randomly  picked.  

Profit:  (Cash  inflow)  –  (running  costs)  –  (what  your  quota  would  have  sold  for),  

Acceptable  profit    Profit  above  some  threshold  that’s  a  func)on  of  what  the  average  par)cipant  in  the  fleet  makes.  

Generates aggregate behaviours known in fisheries if we add these erotetic agents on top of a simulation of the underlying ecology.

There are known aggregate behaviours that occur in fisheries. These frequently occur in responses to policy or environment interventions. In order to test model simulations in the initial phase of the project, we replicate these aggregate behaviours without hard-wiring any response patterns in the agents.

Favoured spot: Fishers   tend   to   have   favorite   spots   they   keep  returning  to,  un)l  depleted  not  acceptably  profitable  anymore

Fishing front: Fishers  tend  to  fish  as  close  to  port  as  possible  to  save  fuel,  )me,  and  effort.  This  generates  a  fishing  front  from  port  

Responding to fishing quotas: focus  on   species  with  high   individual  quota.

Fishing the line: When  a  Marine  Protected  Area   (MPA)   is   installed,  fishers   are   known   to   fish   along   its   line   to   catch   spill-­‐over   of   the  spawn  of  the  target  species  from  within  the  MPA.  

Compliance (conjecture): Compliance  breakdown  once  none  of  the  legal   spots   are   acceptably   profitable   anymore   (in   subsistence  fisheries).  We  show  this  with  an  extreme  MPA.    

Agent-Based ModellingABMs: Agent-Based Models describe behavioural patterns at a population rather than an individual level. ABMs may yield aggregate behavioural patterns that are non-predictable by algorithmic analyses of each individual in isolation (they are computationally intractable).

Advantages of erotetic theory-based model:

-More intelligible than classical economic models to the agents themselves whose industry might be regulated on basis of model (buy-in)-Avoids empirically false assumptions of existing “Explore-exploit-imitate” models.-Fully integrated with a theory of reasoning.-Can allow for both rational and irrational agents.

•  Koralus,   P.,   and   Mascarenhas,   S.   (2013).   The   erote)c   theory   of  reasoning:  bridges  between  formal  seman)cs  and  the  psychology  of  deduc)ve  inference.  Philosophical  Perspec2ves,  27,  312–365.    

•  Mascarenhas,   S.   and   Koralus,   P.   (2016).   Illusory   inferences   with  q u an)fie r s .   Th i n k i n g   a nd   R ea s on i n g ,   hKp : / / d x . do i . o r g /10.1080/13546783.2016.1167125