NATO countries

Method/Variables

OOP/CHE

OOPpc

Milex/GDP

Milexpc

Milex/GGE

ag_Milex/GDP

Levin, Lin & Chu t*

Level

0.304

−7.505***

−4.607***

−0.435

−4.583***

−24.086***

First Difference

−52.19***

−13.748***

Im, Pesaran and Shin W-stat (IPS)

Level

−2.258**

−3.595***

−3.528***

0.355

−3.734***

−16.210***

First Difference

−24.709***

−12.282***

ADF - Fisher Chi-square

Level

88.832**

97.617***

90.989**

65.736

99.837***

510.883***

First Difference

584.324***

262.858***

PP - Fisher Chi-square

Level

335.684***

124.085***

81.028**

49.607

124.294***

564.566***

First Difference

650.419***

275.944***