Skip to main content
. 2018 Nov 23;75:204–214. doi: 10.1016/j.jairtraman.2018.10.002

Table 4.

ADF unit root tests for monthly visitor arrivals by air transport to New Zealand (January 1993‒December 2013).

Countries Constant only
Constant and trend
ln(visitors) Δln(visitors) ln(visitors) Δln(visitors)
Australia −1.27 −6.04*** −0.78 −6.09***
Canada −1.52 −8.76*** −0.02 −37.36***
China −2.46 −5.81*** −2.05 −6.05***
Germany 0.13 −7.27*** −2.06 −7.64***
Japan −0.22 −7.08*** −1.92 −7.18***
South Korea −3.32** −3.85*** −3.31* −3.82**
United Kingdom −1.89 −9.70*** 0.44 −11.02***
United States −1.54 −6.59*** −0.81 −6.69***

Remarks: All the time series above are stated in natural logarithm. Δ denotes the first differencing. The values stated above are t-statistics for the ADF unit root tests. *, ** and *** indicate that the explanatory variable is significant at the 0.10, 0.05, and 0.01 significance level, respectively.