A vector-autoregression-intervention analysis of PKK terrorism and Turkey’s counterterrorism

ABSTRACT

This study analyses the impact of Turkey’s repressive and conciliatory counterterrorism (CT) policies on moderate and extremist members of the terrorist group, Partiye Karkaren Kurdistan (PKK) in the period 1999–2007, using vector autoregression-intervention analysis. By utilising the data about Turkey’s CT against PKK terrorism, the study finds evidence that repressive and conciliatory CT against extremists increases their involvement in terrorist activity, while repression against moderates decreases their involvement in terrorist activity. The model contributes to the current knowledge base of counterterrorism by providing empirical evidence that repressive and conciliatory CT can increase or decrease terrorism, depending on the target population’s degree of solidarity with a terrorist movement.

KEYWORDS:

• Terrorism
• counterterrorism
• VAR
• Turkey
• PKK

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 VAR-intervention analysis was proposed by Enders and Sandler (1993). It generates reliable estimates while accounting for both endogenous and exogenous relationships among variables (Enders & Sandler, 1993).

2 Prospect Theory, a theory in behavioural economics, earned Nobel prize to Kahneman and Tversky in 2002. The theory provides explanation how people decide in risky and uncertain situations. The theory posits that people decide based on perceived loses and gains.

3 The empirical part of this study uses data covering the period 1999–2007. Accordingly, this section primarily provides information about PKK terrorism and Turkey’s CT during that time.

4 Ekici (2006) provides details of the Turkey’s repressive response to PKK in early 1990s. 'Regular army was the most important force, with a deployment of some 145,000 troops in the southeast region in the early 1990s. The army was responsible for conducting counterinsurgency operations, routine patrols, and providing convoy protection to civilian and non-civilian vehicles. Apart from the regular army, two ‘elit units’of commando brigades were created specifically to deal with the PKK. Gendarmerie and its subset ‘Ozel Timler’ were also engaged in the operations since rural areas are in their responsibility in terms of providing security and handling criminal investigations with respect to terrorism. Police forces and their subset ‘Ozel Harekat Timleri’ showed a significant success in the urban areas and attended some operations with the other forces. In addition, Turkish Air Forces, using F-16 and F-104 type of aircrafts and helicopters, attacked the PKK positions in southeastern Turkey, northern Iraq and Iran' (Otucu, 2004; Ekici, 2006).

5 The Granger causality test, proposed by Granger in 1969, produces a measure of how one variable forecasts another. If variable X fails to ‘Granger-cause’ variable Y, we conclude that ‘X is exogenous in the time-series sense with respect to Y’. This statement can also be rephrased as ‘Y is not linearly informative about future X. Granger’s reason for proposing this definition was that if an event Y is the cause of another event X, then the event Y should precede the event X’ (Hamilton 1994, p. 303).

6 The lag length determines the order of VAR.

7 ‘The goal of a VAR analysis is to determine the interrelationships among the [endogenous] variables, not to determine the parameter estimates’ (Enders, 2004, p. 270). The VAR-intervention model in this study provides information about the effects of intervention.

8 Political efficacy is ‘the feeling that individual political action does have, or can have, an impact upon the political process.’ (Craig & Maggiotto, 1982).