Halbrationaler Überschwang

Im Jahr 1996 sah sich der Yale-Ökonom Robert Shiller um, nahm historische Aufzeichnungen unter die Lupe und kam zu dem Schluss, dass der amerikanische Aktienmarkt überbewertet war. Bei hohem Kurs-Gewinn-Verhältnis waren die zukünftigen langfristigen Aktienerträge immer niedrig. Aber nun lagen die Preise der Titel im S&P 500-Index 29 Mal höher als die durchschnittlichen Erträge des letzten Jahrzehnts.

Auf Grundlage der von Shiller und John Campbell von der Harvard-Universität durchgeführten ökonometrischen Regressionsanalyse prognostizierte Shiller im Jahr 1996, dass Titel des S&P 500 im nächsten Jahrzehnt eine schlechte Investition sein werden. Im Jahrzehnt bis Januar 2006, so Shiller, würde der reale Wert von S&P 500-Aktien fallen. Sogar nach Einrechnung der Dividenden schätzte er den wahrscheinlichen Wert investitionsbereinigter Erträge für die S&P 500-Anleger auf null – also weit unter dem ungefähr bei 6 % liegendem jährlichen Ertrag, den man für den amerikanische Aktienmarkt als typisch annahm.

Shillers Argumente waren zwingend. Sie überzeugten Alan Greenspan, der darauf hin am American Enterprise Institute im Dezember 1996 seine berühmte Rede vom „irrationalen Überschwang“ hielt. Und ganz gewiss überzeugten Shillers Argumente auch mich.

To continue reading, please log in or enter your email address.

Registration is quick and easy and requires only your email address. If you already have an account with us, please log in. Or subscribe now for unlimited access.


Log in

  1. Patrick Kovarik/Getty Images

    The Summit of Climate Hopes

    Presidents, prime ministers, and policymakers gather in Paris today for the One Planet Summit. But with no senior US representative attending, is the 2015 Paris climate agreement still viable?

  2. Trump greets his supporters The Washington Post/Getty Images

    Populist Plutocracy and the Future of America

    • In the first year of his presidency, Donald Trump has consistently sold out the blue-collar, socially conservative whites who brought him to power, while pursuing policies to enrich his fellow plutocrats. 

    • Sooner or later, Trump's core supporters will wake up to this fact, so it is worth asking how far he might go to keep them on his side.
  3. Agents are bidding on at the auction of Leonardo da Vinci's 'Salvator Mundi' Eduardo Munoz Alvarez/Getty Images

    The Man Who Didn’t Save the World

    A Saudi prince has been revealed to be the buyer of Leonardo da Vinci's "Salvator Mundi," for which he spent $450.3 million. Had he given the money to the poor, as the subject of the painting instructed another rich man, he could have restored eyesight to nine million people, or enabled 13 million families to grow 50% more food.

  4.  An inside view of the 'AknRobotics' Anadolu Agency/Getty Images

    Two Myths About Automation

    While many people believe that technological progress and job destruction are accelerating dramatically, there is no evidence of either trend. In reality, total factor productivity, the best summary measure of the pace of technical change, has been stagnating since 2005 in the US and across the advanced-country world.

  5. A student shows a combo pictures of three dictators, Austrian born Hitler, Castro and Stalin with Viktor Orban Attila Kisbenedek/Getty Images

    The Hungarian Government’s Failed Campaign of Lies

    The Hungarian government has released the results of its "national consultation" on what it calls the "Soros Plan" to flood the country with Muslim migrants and refugees. But no such plan exists, only a taxpayer-funded propaganda campaign to help a corrupt administration deflect attention from its failure to fulfill Hungarians’ aspirations.

  6. Project Syndicate

    DEBATE: Should the Eurozone Impose Fiscal Union?

    French President Emmanuel Macron wants European leaders to appoint a eurozone finance minister as a way to ensure the single currency's long-term viability. But would it work, and, more fundamentally, is it necessary?

  7. The Year Ahead 2018

    The world’s leading thinkers and policymakers examine what’s come apart in the past year, and anticipate what will define the year ahead.

    Order now