Relative merits of dynamics

[6155GUASTELL@xxxxxxxxxxxxxxx]

Earlier, in reference to a particular contribution involving catastrophe
theory, Jim pondered what the dynamics concepts might do for us, or
for someone else in economics. I haven't read the particular contribution
he described, but, at least in the psychological applications dynamics
contribute two packages of benefits: (1) knowledge of a set of relationships
among variables that are specific in nature, meaning that we know more
about them that simply Y =  A + B + C +...+z. These sets of relationships
could be any of many known dynamical configurations. (2) Accounting for
large amounts of behavior variance. In cases where comparative modeling
has been employed, catastrophe models account for twice as much criterion
variance as comparable linear models with the same qualitative variables
(see my article in March, 1992, PSYCHOLOGICAL BULLETIN.) Now that comparable
testing is now taking place for other dynamics beyond the catastrophes,
I've revised ths 2:1 ratio downward to 1.9:1 (THe BOOK coming out next
spring.)

--Stephen Guastello