Abm Fundamentalism

image: Chernobyl command room Quite a few recent posts receive got examined the might as well as flexibility of ABM models every bit pl...

image: Chernobyl command room

Quite a few recent posts receive got examined the might as well as flexibility of ABM models every bit platforms for simulating a broad arrive at of social phenomena. Joshua Epstein is ane of the high-profile contributors to this field, as well as he is famous for making a peculiarly strong claim on behalf of ABM methods. He argues that “generative” explanations are the uniquely best shape of social explanation. Influenza A virus subtype H5N1 generative explanation is ane that demonstrates how an upper-level construction or causal might comes virtually every bit a resultant of the operations of the units that brand it up. As an aphorism, hither is Epstein's slogan: "If y'all didn't grow it, y'all didn't explicate it." 

Here is how he puts the betoken inwards a Brookings working paper, “Remarks on the foundations of agent-based generative social science” (link; likewise chapter 1 of Generative Social Science: Studies inwards Agent-Based Computational Modeling):

"To the generativist, explaining macroscopic social regularities, such every bit norms, spatial patterns, contagion dynamics, or institutions requires that ane response the next question:

"How could the autonomous local interactions of heterogeneous boundedly rational agents generate the given regularity?

"Accordingly, to explicate macroscopic social patterns, nosotros generate—or “grow”—them inwards agent models." (1)

And Epstein is quite explicit inwards proverb that this formulation represents a necessary status on all putative social explanations: "In summary, generative sufficiency is a necessary, but non sufficient status for explanation." (5).

There is an apparent logic to this persuasion of explanation. However, several before posts cast incertitude on the conclusion. First, nosotros receive got seen that all ABMs necessarily brand abstractive assumptions virtually the behavioral features of the actors, as well as they receive got a hard fourth dimension incorporating "structural" factors similar organizations. We institute that the ABM simulations of ethnic as well as civil conflict (including Epstein's ain model) are radically over-simplified representations of the acre of civil conflict (link).  So it is problematic to assume the full general applicability as well as superiority of ABM approaches for all issues of social explanation.

Second, nosotros receive got likewise emphasized the importance of distinguishing betwixt "generativeness" as well as "reducibility" (link). The quondam is a claim virtually ontology -- the notion that the features of the lower grade suffice to create upwardly one's heed the features of the upper grade through pathways nosotros may non empathise at all. The latter is a claim virtually inter-theoretic deductive relationships -- relationships betwixt our formalized beliefs virtually the lower grade as well as the feasibility of deriving the features of the upper grade from these beliefs. But I argued inwards the before ship service that the fact that Influenza A virus subtype H5N1 is generated past times B does non imply that Influenza A virus subtype H5N1 is reducible to B. 

So in that location appear to endure 2 distinct ways inwards which J. Epstein is over-reaching here: he is assuming that agent-based models tin endure sufficiently detailed to reproduce complex social phenomena similar civil unrest; as well as second, he is assuming without justification that solely reductive explanations are scientifically acceptable.

Consider an representative that provides an explanation of a collective conduct that has explanatory weight, that is non generative, as well as that in all probability could non endure fully reproduced every bit an ABM.  A relevant representative is Charles Perrow's analysis of technology scientific discipline failure every bit a resultant of organizational properties (link). Here is my summary of organizational approaches to the explanation of the incidence of accidents as well as scheme safety:

However, most security experts grip that the social as well as organizational characteristics of the unsafe activity are the most mutual causes of bad security performance. Poor supervision as well as inspection of maintenance operations leads to mechanical failures, potentially harming workers or the public. Influenza A virus subtype H5N1 workplace civilisation that discourages disclosure of unsafe weather condition makes the likelihood of accidental price much greater. Influenza A virus subtype H5N1 communications scheme that permits ambiguous or unclear messages to occur tin atomic number 82 to air crashes as well as wrong-site surgeries. (link)

I would tell that this organizational approach is a legitimate schema for social explanation of an of import effect (the occurrence of large technology scientific discipline failures). Further, it is non a generativist explanation; it does non originate inwards a simplification of a especial variety of failure as well as demonstrate through iterated runs that failures occur X% of the time. Rather, it is based on a dissimilar variety of scientific reasoning, based on causal analysis grounded inwards careful analysis as well as comparing of cases. Process tracing (starting amongst a failure as well as working backwards to discovery the key causal branches that led to the failure) as well as small-N comparing of cases allows the researcher to become inwards at confident judgments virtually the causes of technology scientific discipline failure. And this variety of analysis tin refute competing hypotheses: "operator mistake mostly causes technology scientific discipline failure", "poor technology scientific discipline pattern mostly causes technology scientific discipline failure", or fifty-fifty "technological over-confidence causes technology scientific discipline failure". All these hypotheses receive got defenders; as well as thence it is a noun empirical hypothesis to debate that sure features of organizational deficiency (training, supervision, communications processes) are the most mutual causes of technological accidents.

Other examples from sociology could endure provided every bit well: Michael Mann's explanation of the causes of European fascism (Fascists), George Steinmetz's explanation of variations inwards the characteristics of High German colonial dominion (The Devil's Handwriting: Precoloniality as well as the High German Colonial State inwards Qingdao, Samoa, as well as Southwest Africa), or Kathleen Thelen's explanation of the persistence as well as modify inwards grooming regimes inwards capitalist economies (How Institutions Evolve: The Political Economy of Skills inwards Germany, Britain, the United States, as well as Japan). Each is explanatory, each identifies causal factors that are truly explanatory of the phenomena inwards question, as well as none is generativist inwards Epstein's sense. These are examples drawn from historical sociology as well as institutional sociology; but examples from other parts of the disciplines of sociology are available every bit well.

I sure enough believe that ABMs sometimes provide convincing as well as scientifically valuable explanations. The fundamentalism that I'm taking number amongst hither is the thought that all convincing as well as scientifically valuable social explanations must convey this shape -- a much stronger persuasion as well as ane that is non good supported past times the practise of a arrive at of social scientific discipline inquiry programs.

Or inwards other words, the over-reach of the ABM army camp comes downward to this: the claims of exclusivity as well as full general adequacy of the simulation-based approach to explanation. ABM fundamentalists claim that solely simulations from units to wholes volition endure satisfactory (exclusivity), as well as they claim that ABM simulations tin ever endure designed for whatever work that are mostly adequate to grounding an explanation (general adequacy). Neither suggestion tin endure embraced every bit a full general or universal claim. Instead, nosotros request to recognize the plurality of legitimate forms of causal reasoning inwards the social sciences, as well as nosotros request to recognize, along amongst their strengths, unopen to of the common weaknesses of the ABM approach for unopen to kinds of problems.