\\cserve3\e$\MMG_Docs\worked_out_system_of_decision_about_intervention00.txt
http://www.stat.columbia.edu/~cook/movabletype/archives/2011/05/improvement_of.html
Typing this out for my own benefit. Probably to nobody else's.
You need to build 4 models. [1] A model of the car manufacturers and car market. [2] A model of your negotiation for purchasing a car, and the resources you can bring to bear to the transaction, and the economic constraints you are under for money, time, etc. [3] A model of your hierarchy and compromises between your values and goals. And [4] a model of your rational decision making processes.
Lets call these models [1] "Car-Make", [2] "Car-Buy", [3] "My-Values", [4] "My-Rational"
Per Pearl, since the models "Car-Buy" "My-Values" "My-Rational" need to allow intervention experiments, they have to be expressible as directed acyclic graphs (DAGs). So "Car-Buy" "My-Values" "My-Rational" may be sub-optimal - they are best candidate (or candidates) out of all models that can be expressed as a DAG.
Literature exists to help with the construction of "Car-Make" "Car-Buy". "Car-Make" will model different ways goals can be achieved: you can make a car safer with more weight, or you can make a car safer with superior engineering and judicious use of materials, etc. "Car-Buy" could be informed by a few issues of Consumer Reports, etc.
"My-Values" and "My-Rational" will be constructed with a combination of introspection, objective evidence, tests, and quizzing others. If "My-Values" and "My-Rational" sooth your ego, they will probably perform badly for the task. You want to take every opportunity to have a model be truthful above being a mere advertisement of you being a nice and super nifty guy.
It would seem that "My-Rational" might involve an infinite regress - you have a model, a model of the process that you judge models, a model of the process that you judge models of models, etc. But this flatters the human mind. Per Herbert Simon, Gerd Gigerenzer, Peter M. Todd, Bounded rationality, Ecological Rationality, your really existing system of "My-Values" "My-Rational" is bristling with irresistible fast and frugal heuristics. You can discover these from poor decisions you make time and time again - fast and frugal heuristics work very well in their preferred ecological setting, but are susceptible to failure modes in other settings because they are not ideally rational. (Sure sign of an irresistible fast and frugal heuristic: these are betrayed by poor decisions made time and time again, that are not followed by a relentless implementation of disciplines and restraints to prevent those poor decisions from being made in the future.)
A fast and frugal heuristic expressed as a preference for blondes is not revealed by a string of successful relationships with blondes, because this might be due to good qualities innate in all blondes. A fast and frugal heuristic expressed as a preference for blondes would be revealed by a string of difficult relationships with blondes, and forever indulging a habit of buying drinks for blondes at bars.
There is a tendency to be self-serving in introspection, so objective evidence and third-party observations and judgements are crucial.
Now you can simulate the outcome of a particular choice of automobile, by combining all 4 models into 1 large model and using intervention experiments on the model, suggested by the particular choice of automobile.
Not fully succumbing to the infinite regress, but incorporating a model of how you judge models, could be helpful (call it "Judge-Models"). That way, if multiple suitable models can be imagined and the top candidate does not immediately reveal itself, you have an analytic recourse to determine best fitness. As above, your really existing "Judge-Models" is also bristling with irresistible fast and frugal heuristics, which you can discover... etc...
It would be silly to say a satisfactory decision cannot be made without this level of rigor. But the rigorous fully generalized system can suggest adequate "quick and dirty" substitutes, surely.
I am a faithful reader of Gelman's blog, but I am constantly irritated by his willingness to fashion models of everything _except_ "My-Values" "My-Rational" "Judge-Models", which is the same as crossing the moat and killing the dragon and entering the castle, but refusing to climb up the stairs to the princess in the tower - just sitting there on the first step.
Without discussion of "My-Values" "My-Rational" "Judge-Models", you have done so much preparation for a decision about an intervention (calling inaction its own kind of intervention)... but then dropped the bride at the threshold.
Supplying "My-Values" "My-Rational" "Judge-Models" violates the stereotypical separation of work/concern/responsibility between the academic and the decision maker and the action taker, so the reluctance to discuss them is completely understandable, and my irritation is unreasonable, I know.
