Monday, June 8, 2015

Say What?

The latest CairnsWatch from Rick Carr at HTW popped into the inbox on Friday afternoon. Rick reckons the trend rate of growth for domestic passengers at Cairns Airport is:
Over the period from April 2014 to April 2015 domestic passenger numbers have shown an 8.2% trend increase.  
You can see my previous posts on Airport traffic in recent months:

 Airport growth continues in March; International recovery continues at airport

In my comments on the February numbers I quietly questioned the CairnsWatch trend numbers on this with reference to Chinese New Year. With late release of the March airport numbers this latest CairnsWatch provides a further trend percentage boost after another two months which I just can't stack up with any underlying data from the Airport.

I have checked the CairnsWatch archive but just can't make sense of the reported monthly variation in the trend numbers which did a massive jump in a month between January and February. I don't want to be critical of Rick who is a lovely guy but some of his trend numbers just don't work for me. I'm sticking with my numbers which are also not dissimilar to reported numbers from Cairns Airport and stakeholder Auckland Airport.

Reported in the Cairns Post: Airport and building approvals give rise to Cairns’ economic turnaround

1 comment:

  1. I've noticed there are some funny trend lines in that Cairns Watch report, trend lines I can't reconcile with any moving average filter I'm aware of. I'd say you're right to be skeptical if there is no explanation of how the trend line is derived and it doesn't appear to make sense.