Towards the Methodological Turn in the Philosophy of Science - Mechanism and Causality in Biology and Economics - page 8

Input → Mechanism → Output
Fig. 1.1 The Bungean input-output mechanism (Adopted from Bunge 2004 )
terms of such an artifact is commonplace in both natural and social sciences, since
such visualization helps understand the various aspects of mechanisms and how
they are constituted. A mousetrap, for instance, is used by Craver and Bechtel
( 2006 ) to illustrate the philosophical notion of mechanism. In social science,
underneath different definitions of social mechanisms we previously discussed is
a strong perception of the society as a machine. An example is Elster's assertion
that an explanation in social science requires of specifying social cogs and wheels.
According to Elster ( 1983 , p. 24), “To explain is to provide a mechanism, to open
up the black box and show the nuts and bolts, the cogs and wheels of the internal
machinery.” For Bunge, a mechanism is specifically perceived as an input-output
machine, which is contrasted with black boxes by which inputs and output are
connected without knowing the inner machinery (Bunge 2004 ; Hedstr¨m and
Swedberg 1998 ), and can be understood in terms of the diagram in Fig. 1.1 .
In economics, economists have also been using and adopting the concept of
mechanism for centuries. As Harro Maas ( 2005 ) demonstrates, the practices of
mechanical reasoning among the political economists had been observed in Victo-
rian Britain, where the economic world—perhaps analogous to the physical
world—was envisaged as a machine. More specifically, the type of machine is an
input-output machine, coinciding with the Bungean input-output mechanism. There
are two salient cases in the economic literature. First, the “market mechanism,”
which is perhaps the most fundamental concept indicating the structure and capac-
ity of the market for allocating the resources among economic units, is commonly
understood as such. To study economic mechanisms, a subfield mechanism design
emerged in the 1960s to apply proper mathematical tools to construct and analyze
how economic units and activities are coordinated and guided through the informa-
tion they receive from a fictitious “information center.” A mechanism is thus also
viewed as a communication or a dialogue between the information center and
economic units or “periphery” (Hurwicz 1973 , pp. 6-7). In this regard, economic
mechanisms bear some similarity to mental mechanisms as they both are informa-
tion-processing mechanisms (c.f., Bechtel 2008 ). Second, the input-output analysis ,
which was established in the 1930 by the economist Wassily Leontief, explicitly
treats the structure of an economy as constituted by input-output relationships. With
its ambition to quantitatively deal with all components of the economy, the input-
output analysis requires its models to be computable and statistically measurable so
that it can describe and interpret the economic operations in terms of “directly
observable basic structural relationships” (Leontief 1987 , p. 860).
However, as of now, it seems causality rather than mechanism is economists'
primary concern. Mechanism in general is understood in the context of “causal
mechanism,” whose structure—causal structure—needs to be identified. Kevin
Hoover ( 2001 , p. 24) offers one definition of causal structure as “a network of