Book Cover

The availability heuristic, introduced in Chapter 12,  states that we make judgments about an attribute based on how easy or hard it is to retrieve information about the attribute. In Chapter 13, Kahneman dives deeper into how the availability heuristic functions and provides some hints on how it can be used.

The chapter begins with a discussion of how availability impacts behavior. I lived in Louisiana for several years and occasionally visit family in the area.  Floods are one of the constants of the geography of the southern part of the state (great food is another). I remember in college reading articles about how the levees and pumps in New Orleans were inadequate if a more powerful storm hit the region than had seen before.  The defenses were constructed based on what had been seen before (the availability heuristic). Then Katrina happened. Most software development processes are originally built to be lean and efficient based experience (availability). However, life then intervenes and processes are amended based on new problems that are encountered (availability again).  Over time what was once lean and efficient is bloated with checks for every problem the organization has encountered regardless of the probability of recurrence. The availability heuristic contributes significantly to this behavior.

At a more macro level availability impacts behavior through a common 3-step pattern in which a significant event occurs, Hurricane Katrina for example.  The event is followed by concern and action. Kahneman references data about the number of earthquake policies written after the last major quake in San Francisco. However, as time goes by, complacency reasserts itself (step 3).  In New Orleans, new building moves forward in flood-prone areas and in California insurance policies lapse. As someone leading and managing change for many years, I have seen and lived through this pattern. An event or fad generates a need to change which is followed by action and the inevitable time when the next big thing causes complacency. The pattern is called an availability cascade.

Emotions, how we feel about something, contribute to the affect heuristic. The affect heuristic, which is defined as people making based on whether they like something or not. The affect and availability heuristics are intertwined. In the software world the media (print and digital) trumpet a new idea, the cool kids jump on the idea causing natural attraction to the idea. There is an excellent line in the chapter that describes the affect heuristic, “the emotional tail wags the rational dog.” Understanding the linkage between availability and affect heuristics suggests different change management strategies based on context.

The final idea in the chapter begins with a reminder that every policy includes an assumption of human nature.  All policies, procedures, and guidelines make assumptions about the choices that people may make and the consequences of their choices. The assumptions lead to tension between people make decisions based on emotions and expert input which is theoretically dispassionate. That tension can cause a populist reaction based on the affect heuristic causing experts to be excluded from decisions (or selective choice of experts).  Eschewing experts can lead to manipulation by a significant amount of availability bias which then can cascade out of control.

Remember, if you do not have a favorite, dog-eared copy of Thinking, Fast and Slow, please buy a copy.  Using the links in this blog entry helps support the blog and its alter-ego, The Software Process and Measurement Cast. Buy a copy on Amazon,  It’s time to get reading!  


The installments:

Week 1: Logistics and Introduction

Week 2: The Characters Of The Story

Week 3: Attention and Effort

Week 4: The Lazy Controller

Week 5: The Associative Machine

Week 6: Cognitive Ease

Week 7: Norms, Surprises, and Causes

Week 8: A Machine for Jumping to Conclusions 

Week 9: How Judgement Happens and Answering An Easier Question 

Week 10:  Law of Small Numbers 

Week 11: Anchors 

Week 12: The Science of Availability