Makroökonomen Jonathan Tepper erklärt das Phänomen am Beispiel von Sand-Lawinen (und Buschfeuern). Sandberge scheinen stabil, und man kann im Laufe der Jahre immer mehr Körnchen auftürmen. Bis dann irgendwann das letzte Körnchen eines zuviel war. Dann kommt alles fürchterlich ins Rutschen und wird zur Lawine.
Ähnliche "Paradigmenwechsel" (urplötzliche Übergänge von scheinbarer Stabilität zu gigantischem Rutschen) gibt es auch in politischen Systemen und ganzen Wirtschaftsordnungen. Und erst recht an der Börse.
unherd.com/2020/03/...19-has-exposed-our-financial-fragility/
In politics and economics, massive change events tend to happen not in orderly sequences, but in sudden spasms, like the Arab Spring, or the collapse of the Eastern Bloc. Watching events unfold is often like watching sand grains pile slowly on top of one another until a final, random grain causes the entire pile to collapse. People knew the Arab countries were fragile and that the Eastern Bloc might eventually fall, but predicting which grain of sand would do it precipitate either was impossible.
Physicists call these transitions critical thresholds. Critical thresholds are everywhere in nature. Water at moderate temperatures is disorganised and free-flowing, yet at a given critical value, it has an abrupt transition to a solid. It’s the same with the sandpile: one grain too many can trigger collapse — but which one?
In 1987 Per Bak, Chao Tang, and Kurt Wiesenfeld found that while sandpiles may be individually unpredictable, they all behave the same way. The critical finding of their experiments was that the distribution of sand avalanches obeys a mathematical power law: The frequency of avalanches is inversely proportional to their size. Much like forest fires, the less frequent they are, the more catastrophic they are.
It’s the same with financial markets and the economy. We will experience years of quiet, interrupted by sudden avalanche. Years of slowly adding grains of sand [A.L.: Schulden!] can end abruptly — to our great surprise. Today in financial markets, many unsustainable trends have been building, and the coronavirus is merely the grain of sand that has tipped the sandpile....