Patterns of Transnational Terrorism, 1970–1999: Alternative Time-Series Estimates

Using alternative time-series methods, this paper investigates the patterns of transnational terrorist incidents that involve one or more deaths. Initially, an updated analysis of these fatal events for 1970–1999 is presented using a standard linear model with prespecified interventions that represent significant policy and political impacts. Next, a (regime-switching) threshold autoregressive (TAR) model is applied to this fatality time series. TAR estimates indicate that increases above the mean are not sustainable during high-activity eras, but are sustainable during low-activity eras. The TAR model provides a better fit than previously tried methods for the fatality time series. By applying a Fourier approximation to the nonlinear estimates, we get improved results. The findings in this study and those in our earlier studies are then applied to suggest some policy implications in light of the tragic attacks on the World Trade Center and the Pentagon on September 11, 2001.

[1]  Walter Enders,et al.  Causality between transnational terrorism and tourism: The case of Spain , 1991 .

[2]  Jon Cauley,et al.  Intervention Policy Analysis of Skyjackings and Other Terrorist Incidents , 1988 .

[3]  Walter Enders,et al.  Terrorism and foreign direct investment in spain and greece , 1996 .

[4]  Martha Crenshaw,et al.  Why Violence SpreadsThe Contagion of International Terrorism , 1980 .

[5]  K. Chan,et al.  Consistency and limiting distribution of the least squares estimator of a threshold autoregressive model , 1993 .

[6]  R. Davies.  Hypothesis Testing when a Nuisance Parameter is Present Only Under the Alternatives , 1987 .

[7]  T. Sandler,et al.  A Theoretical Analysis of Transnational Terrorism , 1983, American Political Science Review.

[8]  Alex P. Schmid,et al.  Political Terrorism: A New Guide to Actors, Authors, Concepts, Data Bases, Theories, and Literature , 1984 .

[9]  Walter Enders,et al.  Transnational Terrorism in the Post–Cold War Era , 1999 .

[10]  Todd Sandler,et al.  International terrorism in the 1980s : a chronology of events , 1989 .

[11]  Bruce Hoffman,et al.  The confluence of international and domestic trends in terrorism , 1997 .

[12]  Paul Wilkinson,et al.  Terrorism Versus Democracy: The Liberal State Response , 2000 .

[13]  Walter Enders,et al.  Estimating non-linear ARMA models using Fourier coefficients , 2000 .

[14]  Walter Enders,et al.  The Effectiveness of Antiterrorism Policies: A Vector-Autoregression-Intervention Analysis , 1993, American Political Science Review.

[15]  T. Sandler,et al.  Is Transnational Terrorism Becoming More Threatening? , 2000 .

[16]  Hung Man Tong,et al.  Threshold models in non-linear time series analysis. Lecture notes in statistics, No.21 , 1983 .

[17]  John A. C. Conybeare,et al.  Retaliating against Terrorism: Rational Expectations and the Optimality of Rules versus Discretion , 1994 .

[18]  Walter Enders,et al.  A time‐series analysis of transnational terrorism: Trends and cycles , 1992 .

[19]  Yonah Alexander.  Europe's Red Terrorists: The Fighting Communist Organizations , 1992 .

[20]  John Scott.  Media congestion limits media terrorism , 2001 .

[21]  Clive W. J. Granger,et al.  Unit Root Tests and Asymmetric Adjustment with an Example Using the Term Structure of Interest Rates , 1998 .

[22]  Ruey S. Tsay,et al.  Testing and Modeling Threshold Autoregressive Processes , 1989 .

[23]  P. Nelson.  Terrorism and the media: An empirical analysis , 1992 .

[24]  H. Tong,et al.  Threshold Autoregression, Limit Cycles and Cyclical Data , 1980 .

[25]  Andrew Harvey,et al.  Forecasting, Structural Time Series Models and the Kalman Filter , 1990 .

[26]  Todd Sandler,et al.  The calculus of dissent: An analysis of terrorists' choice of targets , 1988, Synthese.

[27]  Helmut Lütkepohl,et al.  Introduction to multiple time series analysis , 1991 .

[28]  Todd Sandler,et al.  Global Challenges: An Approach to Environmental, Political, and Economic Problems , 1997 .

[29]  Walter Enders,et al.  Assessing the impact of terrorist‐thwarting policies: An intervention time series approach , 1990 .