Tuesday, 12 October 2021

Modelling

 

"A recent article in Stuff does a good job of explaining the science behind mathematical modelling. But the article suffers from two glaring fallacies.
    "First, the article fails to recognise that these S.I.R. models [in which the population is assigned to compartments with the labels S, I, or R (Susceptible, Infectious, or Recovered)] are certainly a way of looking at disease propagation, but they are certainly not the only way; in fact, they are not even a very good way since they are highly stylised and based on restrictive assumptions....
    They may be useful in understanding the path of disease propagation in the early stages of a new disease. But beyond a point, the usefulness of such models is limited.... In the age of big data and rapid advances in data science, excessive reliance on 'toy' mathematical models is misguided.
    "The second problem plaguing this type of analysis in New Zealand is lack of peer review and quality assurance. This is something that NZ journalists just do not understand; the need to have research results validated by objective referees to have any faith in the conclusions. This lack of review is partly why, using the same modelling techniques, researchers at Auckland come up with numbers that are seriously at odds with those reported by people at the University of Otago....
    "You need objective assessors around the table to play devil’s advocate.
    "Unless we insist on better, evidence-based policy and quality assured research, our policy responses will continue to fall short."
          ~ Ananish Chaudhuri (Professor, Author, Commentator & Purveyor of Common Sense)
Further

"S.I.R. models in Covid are actually 1.5 years behind the current understanding of the consequences of Covid-19 policies, and half-century behind the macroeconomic understanding of human behaviour (the Lucas critique on ignoring human behaviour in macro). They are entirely obsolete for policymaking because they ignore human and government responses. 
    "This is daftly comical exactly because a) the governments impose restrictions and b) people do adjust behaviour (distancing, masks, work from home,... think the US or Sweden)... This is the nuance that is informing policymakers abroad! 
    "Here in SIR Hendyland, we [instead] lay sacrifices at the altar of a debunked model of zero behavioural responses, and the heretics are promptly stoned. There is an active suppression of informed discourse. In large part, this happened due to zero openness, zero scrutiny, hence zero accountability. And the media are to blame, I'm sorry to say."
          ~ Martin Berka (Professor of Macroeconomics at Massey University)


1 comment:

  1. Wow Martin. Tell us what you really think ;-)
    Unleash your inter honey badger!

    ReplyDelete

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