that may help drive economic events. By a confluence, I mean a group of
narratives that are not viewed as particularly associated with one another but that
have similar economic effects at a point in time and so may explain an
exceptionally large economic event. For example, in my 2000 book Irrational
Exuberance, I listed a dozen precipitating factors, or narratives, that happened to
occur together around 2000 to create the most elevated stock market in the
United States ever, soon to be followed by a crash. The list, in brief, comprised
the World Wide Web, the triumph of capitalism, business success stories,
Republican dominance, baby boomers retiring, business media expansion,
optimistic analysts, new retirement plans, mutual funds, decline of inflation,
expanding volume of trade, and rising culture of gambling. If we want to know
why an unusually large economic event happened, we need to list the seemingly
unrelated narratives that all happened to be going viral at around the same time
and affecting the economy in the same direction. However, it is important to
recognize that big economic events usually can’t be described as caused by just a
single constellation of narratives. It is far more likely that big economic events
are not explainable in such satisfying terms. Instead, explaining those events
requires making a list of economic narratives that itself cannot be described as a
simple story or a contagious narrative.
In part III of this book, we focus on some of the brighter stars in the narrative
constellations, those that are significant enough to contribute substantially to
changes in economic motivations. We cannot yet link these constellations
precisely to severe economic events. But even with partial views of the
constellations and confluences, we are making progress toward understanding
the events.
We also have no more than a partial view of the forces that make some
narratives into epidemics. The ability of narratives to “go viral” is something of
a mystery, which we attempt to unravel in the next chapter.

Chapter 4
Why Do Some Narratives Go Viral?
It is difficult to state accurately or to quantify the reason a few economic
narratives go viral while most fail to do so. The answer lies in a human element
that interacts with economic circumstances. Beyond some simple and predictable
regularities, a network of human minds sometimes acts almost like a random
number generator in selecting which narratives go viral. The apparent
randomness in outcomes has to do with randomness in the mutation of stories to
more contagious forms, and with moments of our individual lives and attentions,
that can lead to a sudden climax of public attention to specific narratives. We
routinely find ourselves puzzling years later over the reasons for the success of
popular narratives in history and for their economic consequences.

The Spontaneity of Narratives in Human Thinking and Actions
At the beginning of the twentieth century, scholars from a wide array of
disciplines began to think that narratives, stories that seem to have entertainment
value only, are central to human thinking and motivation. For example, in 1938
the existentialist philosopher Jean-Paul Sartre wrote,
A man is always a teller of tales, he lives surrounded by his stories and the
stories of others, he sees everything that happens to him through them; and he
tries to live his life as if he were recounting it.1
The story of oneself and the stories one tells about others inevitably have diverse
connections to what we call “human interest,” either directly or indirectly.
When we are asleep at night, narratives appear to us in the form of dreams.
We do not dream of equations or geometric figures without some human
element. Neuroscientists have described dreaming, which involves characters,
settings, and a hierarchical event structure, as based on a storytelling instinct. In
fact, the brain’s activity during dreaming resembles the activity of certain
damaged brains, in which lesions of the anterior limbic system and its
subcortical connections lead to spontaneous confabulation.2
In their attempts to understand social movements, sociologists have begun to
think of the contagion of narratives as central to social change. For example,
sociologist Francesca Polletta, who studied the sit-in social movement of the
1960s in which white Americans participated in protests of discrimination
against blacks, reported that students described the demonstrations as unplanned,
impulsive, “like a fever,” and “over and over again, spontaneous.”3 These
demonstrations were often driven by a particular popular narrative about blacks
demanding service at lunch counters that were labeled as “white only,”
accompanied by young white supporters who showed moral outrage at the
exclusion of blacks. This kind of protest, christened the “sit-in,” ultimately
became a symbol of a new social movement.
The sit-in story emerged from a single story about a February 1, 1960, protest
involving four students from Greensboro Agricultural and Technical College.
The story revolved around polite young black people who ignored orders to
leave the lunch counter where blacks were not served. The young people sat
patiently, waiting to be served, until the restaurant closed, and they returned the