Mandelbrot’s Levy distributions failed as a research cascade because they were analytically intractable.

Evidence

When research productivity, peer recognition, and publication are prized, another essential quality of a “good” model is that it can be the foundation for further research that is itself tractable without being trivial. All the “orthodox” models centrally considered here had that feature. Consider, in contrast, Mandelbrot’s infinite-variance Levy distributions, another case of a cascade that began (with Fama building on Mandelbrot’s work, and Fama’s students, especially Richard Roll, then taking up the Levy model in their turn) but then lost almost all momentum. Infinite variances undercut standard components of the economist’s and econometrician’s intellectual toolkit, while what Levy distributions had to offer in their stead could seem dauntingly intractable. — Donald MacKenzie, An Engine, Not a Camera, 1103

Categorization

• DEFINE: Clarifies why tractability is a core selection criterion for model adoption — models must seed further tractable research.
• XREF: Echoes the cascade/adoption framework from earlier chapters on how models spread through research communities. — connects to: Personal career calculus, not just evidence, shaped academics’ abandonment of Levy distributions — Donald MacKenzie, An Engine, Not a Camera: How Financial…, 511; Mandelbrot’s Levy distribution evidence was largely graphical and informal — Donald MacKenzie, An Engine, Not a Camera: How Financial…, 504; Empirical aggregation tests undercut the Levy distribution’s self-similarity claim — Donald MacKenzie, An Engine, Not a Camera: How Financial…, 507 (+3 more)

Broader Connections

• The Levy distribution’s failure to survive time aggregation cooled academic interest in fat tails #expands (0.85) — Donald MacKenzie, An Engine, Not a Camera, 509
• Mandelbrot’s Levy distribution evidence was largely graphical and informal #expands (0.78) — Donald MacKenzie, An Engine, Not a Camera, 504
• Mainstream statistics training in the 1970s ignored Levy distributions #corroborates (0.75) — Donald MacKenzie, An Engine, Not a Camera, 481
• Empirical aggregation tests undercut the Levy distribution’s self-similarity claim #qualifies (0.72) — Donald MacKenzie, An Engine, Not a Camera, 507
• Adopting Levy distributions would invalidate nearly all classical econometric methods #corroborates (0.72) — Donald MacKenzie, An Engine, Not a Camera, 505