Systems Thinking about the Crash of ’29

I picked up John Kenneth Galbraith’s account of The Great Crash at a used bookstore. I’m not far into it, but there’s a nice assertion of the importance of a systemic view over event-based descriptions right at the start:

… implicit in this hue and cry was the notion that somewhere on Wall Street … there was a deus ex machina who somehow engineered the boom and bust. This notion that great misadventures are the work of great and devious adventurers, and that the latter can and must be found if we are to be safe, is a popular one in our time. … While this may be a harmless avocation, it does not suggest and especially good view of historical processes. No one was responsible for the great Wall Street crash. No one engineered the speculation that preceded it. Both were the product of the free choice of hundreds of thousands of individuals. The latter were not led to the slaughter. They were impelled to it by the seminal lunacy which has always seized people who are seized in turn with the notion that they can become very rich. …

Galbraith’s purpose in writing the book is itself systemic, to weaken the erosion of memory that permits episodic boom bust cycles:

Someday, no one can tell when, there will be another speculative climax and crash. There is no chance that, as the market moves to the brink, those involved will see the nature of their illusion and so protect themselves and the system. … There is some protection so long as there are people who know, when they hear it said that history is being made in this market or that a new era has been opened, that the same history has been made and the same eras have been opened many, many times before. This acts to arrest the spread of illusion. …

With time, the number who are restrained by memory must decline. The historian, in a volume such as this, can hope that he provides a substitute for memory that slightly stays that decline.

 

A puzzling bias against experimentation

Objecting to experiments that compare two unobjectionable policies or treatments

Randomized experiments have enormous potential to improve human welfare in many domains, including healthcare, education, finance, and public policy. However, such “A/B tests” are often criticized on ethical grounds even as similar, untested interventions are implemented without objection. We find robust evidence across 16 studies of 5,873 participants from three diverse populations spanning nine domains—from healthcare to autonomous vehicle design to poverty reduction—that people frequently rate A/B tests designed to establish the comparative effectiveness of two policies or treatments as inappropriate even when universally implementing either A or B, untested, is seen as appropriate. This “A/B effect” is as strong among those with higher educational attainment and science literacy and among relevant professionals. It persists even when there is no reason to prefer A to B and even when recipients are treated unequally and randomly in all conditions (A, B, and A/B). Several remaining explanations for the effect—a belief that consent is required to impose a policy on half of a population but not on the entire population; an aversion to controlled but not to uncontrolled experiments; and a proxy form of the illusion of knowledge (according to which randomized evaluations are unnecessary because experts already do or should know “what works”)—appear to contribute to the effect, but none dominates or fully accounts for it. We conclude that rigorously evaluating policies or treatments via pragmatic randomized trials may provoke greater objection than simply implementing those same policies or treatments untested.

Stress, Burnout & Biology

In my last post, stress takes center stage as both a driver and an outcome of the cortisol-cytokine-serotonin system. But stress can arise endogenously in another way as well, from the interplay of personal goals and work performance. Jack Homer’s burnout model is a system dynamics classic that everyone should explore:

Worker burnout: A dynamic model with implications for prevention and control

Jack B. Homer

This paper explores the dynamics of worker burnout, a process in which a hard‐working individual becomes increasingly exhausted, frustrated, and unproductive. The author’s own two‐year experience with repeated cycles of burnout is qualitatively reproduced by a small system dynamics model that portrays the underlying psychology of workaholism. Model tests demonstrate that the limit cycle seen in the base run can be stabilized through techniques that diminish work‐related stress or enhance relaxation. These stabilizing techniques also serve to raise overall productivity, since they support a higher level of energy and more working hours on the average. One important policy lever is the maximum workweek or work limit; an optimal work limit at which overall productivity is at its peak is shown to exist within a region of stability where burnout is avoided. The paper concludes with a strategy for preventing burnout, which emphasizes the individual’s responsibility for understanding the self‐inflicted nature of this problem and pursuing an effective course of stability.

You can find a copy of the model in the help system that comes with Vensim.

DYNAMO

Today I was looking for DYNAMO documentation of the TRND macro. Lo and behold, archive.org has the second edition of the DYNAMO User Guide online. It reminds me that I was lucky to have missed the punch card era:

… but not quite lucky enough to miss timesharing and the teletype:

The computer under my desk today would have been the fastest in the world the year I finished my dissertation. We’ve come a long way.

Happy E day

E, a.k.a. Euler’s number or the base of the natural logarithm, is near and dear to dynamic modelers. It’s not just the root of exponential growth and decay; thanks to Euler’s Formula it encompasses oscillation, and therefore all things dynamic.

E is approximately 2.718, and today is 2/7/18, at least to Americans, so this is the biggest e day for a while. (NASA has the next 1,999,996 digits, should you need them.) Unlike π, e has not been contested in any state legislature that I know of.