Explosive Behavior in the 1990s' NASDAQ: When Did Exuberance Escalate Asset Values?

A recursive test procedure is suggested that provides a mechanism for testing explosive behavior, date-stamping the origination and collapse of economic exuberance, and providing valid confidence intervals for explosive growth rates. The method involves the recursive implementation of a right-side unit root test and a sup test, both of which are easy to use in practical applications, and some new limit theory for mildly explosive processes. The test procedure is shown to have discriminatory power in detecting periodically collapsing bubbles, thereby overcoming a weakness in earlier applications of unit root tests for economic bubbles. Some asymptotic properties of the Evans (1991) model of periodically collapsing bubbles are analyzed and the paper develops a new model in which bubble duration depends on the strength of the cognitive bias underlying herd behavior in the market. The paper also explores alternative propagating mechanisms for explosive behavior based on economic fundamentals under time varying discount rates. An empirical application to the Nasdaq stock price index in the 1990s provides confirmation of explosiveness and date-stamps the origination of financial exuberance to June 1995, prior to the famous remark in December 1996 by Alan Greenspan about irrational exuberance in financial markets, thereby giving the remark empirical content.

[1]  Jun Yu,et al.  Limit Theory for Dating the Origination and Collapse of Mildly Explosive Periods in Time Series Data , 2009 .

[2]  K. Knight,et al.  No Country for Old Unit Root Tests: Bridge Estimators Differentiate between Nonstationary Versus Stationary Models and Select Optimal Lag , 2008 .

[3]  P. Phillips,et al.  Limit Theory for Moderate Deviations from Unity , 2007 .

[4]  Christian Gourieroux,et al.  Indirect Inference for Dynamic Panel Models , 2006 .

[5]  Irrational Exuberance.  Irrational exuberance? , 2006, Nature Biotechnology.

[6]  Pietro Veronesi,et al.  Technological Revolutions and Stock Prices , 2005 .

[7]  Apostolos Serletis,et al.  Rational bubbles or persistent deviations from market fundamentals , 2005 .

[8]  L. Gil‐Alana,et al.  A test for rational bubbles in the NASDAQ stock index: A fractionally integrated approach , 2005 .

[9]  R. Gürkaynak.  Econometric Tests of Asset Price Bubbles: Taking Stock , 2005 .

[10]  Peter C. B. Phillips,et al.  Limit Theory for Moderate Deviations from a Unit Root , 2004 .

[11]  Markus K. Brunnermeier,et al.  Hedge Funds and the Technology Bubble , 2003 .

[12]  R. Thaler,et al.  Can the Market Add and Subtract? Mispricing in Tech Stock Carve‐outs , 2003, Journal of Political Economy.

[13]  P. Phillips,et al.  Nonstationary Discrete Choice , 2002 .

[14]  Melvyn J. Weeks,et al.  Simulation-based Inference in Econometrics: Simulation-based inference in econometrics: methods and applications , 2008 .

[15]  Michael J. Cooper,et al.  A Rose.Com by Any Other Name , 2000 .

[16]  Wenjiang J. Fu,et al.  Asymptotics for lasso-type estimators , 2000 .

[17]  Peter C. B. Phillips,et al.  Nonstationary Binary Choice , 2000 .

[18]  Eduardo S. Schwartz,et al.  Rational Pricing of Internet Companies , 2000 .

[19]  J. Olivier.  Growth-Enhancing Bubbles , 2000 .

[20]  Richard H. Thaler,et al.  The End of Behavioral Finance , 1999 .

[21]  Zacharias Psaradakis,et al.  Detecting periodically collapsing bubbles: a Markov‐switching unit root test , 1999 .

[22]  A. Lo,et al.  THE ECONOMETRICS OF FINANCIAL MARKETS , 1996, Macroeconomic Dynamics.

[23]  Yangru Wu.  RATIONAL BUBBLES IN THE STOCK MARKET: ACCOUNTING FOR THE U.S. STOCK‐PRICE VOLATILITY , 1997 .

[24]  James G. MacKinnon,et al.  Approximate bias correction in econometrics , 1998 .

[25]  A. Borodin,et al.  Handbook of Brownian Motion - Facts and Formulae , 1996 .

[26]  N. Touzi,et al.  Calibrarion By Simulation for Small Sample Bias Correction , 1996 .

[27]  Serena Ng,et al.  Unit Root Tests in ARMA Models with Data-Dependent Methods for the Selection of the Truncation Lag , 1995 .

[28]  D. Kohn.  Minutes of the Federal Open Market Committee Meeting Held on September 30, 1997 , 1994 .

[29]  Anthony A. Smith,et al.  Estimating Nonlinear Time-Series Models Using Simulated Vector Autoregressions , 1993 .

[30]  John W. Galbraith,et al.  Testing for a Unit Root , 1993 .

[31]  D. Andrews.  Exactly Median-Unbiased Estimation of First Order Autoregressive/Unit Root Models , 1993 .

[32]  J. Stock,et al.  Recursive and Sequential Tests of the Unit-Root and Trend-Break Hypotheses: Theory and International Evidence , 1992 .

[33]  G. Evans,et al.  On the Robustness of Bubbles in Linear RE Models , 1992 .

[34]  G. Evans.  Pitfalls in Testing for Explosive Bubbles in Asset Prices , 1991 .

[35]  Mark Schilling,et al.  The Longest Run of Heads , 1990 .

[36]  Robert P. Flood,et al.  On Testing for Speculative Bubbles , 1990 .

[37]  Stock price volatility , 1990 .

[38]  Kenneth A. Froot,et al.  Intrinsic Bubbles: the Case of Stock Prices , 1989 .

[39]  George W. Evans,et al.  The fragility of sunspots and bubbles , 1989 .

[40]  Bubbles, Fads and Stock Price Volatility Tests: A Partial Evaluation: Discussion , 1988 .

[41]  K. West,et al.  Bubbles, Fads, and Stock Price Volatility Tests: a Partial Evaluation , 1988 .

[42]  Herschel I. Grossman,et al.  Explosive Rational Bubbles in Stock Prices , 1988 .

[43]  W. Andrew,et al.  LO, and A. , 1988 .

[44]  Herschel I. Grossman,et al.  On the Inception of Rational Bubbles , 1987 .

[45]  P. Phillips.  Time series regression with a unit root , 1987 .

[46]  Robert J. Shiller,et al.  Cointegration and Tests of Present Value Models , 1987, Journal of Political Economy.

[47]  B. Efron.  The jackknife, the bootstrap, and other resampling plans , 1987 .

[48]  P. Phillips.  Testing for a Unit Root in Time Series Regression , 1988 .

[49]  R. Shiller,et al.  The Dividend-Price Ratio and Expectations of Future Dividends and Discount Factors , 1986 .

[50]  K. West.  A Specification Test for Speculative Bubbles , 1986 .

[51]  Robert P. Flood,et al.  Asset Price Volatility, Bubbles, and Process Switching , 1986 .

[52]  J. Tirole.  ASSET BUBBLES AND OVERLAPPING GENERATIONS , 1985 .

[53]  R. Shiller.  Stock Prices and Social Dynamics , 1984 .

[54]  Robert P. Flood,et al.  On the equivalence of solutions in rational expectations models , 1983 .

[55]  J. Tirole.  On the Possibility of Speculation under Rational Expectations , 1982 .

[56]  M. Watson,et al.  Bubbles, Rational Expectations and Financial Markets , 1982 .

[57]  J. Robert,et al.  SHILLER, . Do Stock Prices Move Too Much to be Justified by Subsequent Changes in Dividends?, The American Economic Review, , . , 1981 .

[58]  Robert P. Flood,et al.  Market Fundamentals versus Price-Level Bubbles: The First Tests , 1980, Journal of Political Economy.

[59]  O. Blanchard,et al.  Speculative bubbles, crashes and rational expectations , 1979 .

[60]  Chris Chatfield,et al.  Introduction to Statistical Time Series. , 1976 .

[61]  M. H. Quenouille.  NOTES ON BIAS IN ESTIMATION , 1956 .

[62]  Maurice G. Kendall,et al.  NOTE ON BIAS IN THE ESTIMATION OF AUTOCORRELATION , 1954 .