Does the frequency of airline strikes correlate with profitability? CAPA’s word count suggests so

Over the past decade CAPA has tracked the number of news articles on its website that mention the word "strike". CAPA annually produces approximately 120,000 global news stories and 7.2 million words, translated from over 30 languages, so the statistics are fairly representative.
This "strike" metric has broadly followed the airline profit cycle in the past - not surprising, since labour is typically more demanding when the profit cycle is at its peak.
There have recently been some notable recent mentions of the 's' word in connection with European airlines. SAS suffered a pilot strike in Apr-2019 and May-2019 and British Airways, Eurowings, easyJet and Ryanair are among airlines that have been linked with the threat of strikes this summer. There have also been strikes at European airports and ATC organisations this year.
However, since peaking in 2016, the annual number of strike-related articles has been on a downward path. So too has the annual operating profit margin of the world airline industry. In 1H2019 the number fell by just over one third. If this rate of decline continued for the whole year, 2019 would have the lowest number of such articles since 2009.
A reduction in industrial action is welcome, but less so if it signals a further decline in the airline profit cycle.