[viknesh]

One thing you might not have considered is that some notion of "dissatisfaction w/ job" would increase both the likelihood of you wanting to join a union and your employer wanting to fire you or lay you off.

Edit: also, another confounding factor that hasn't been discussed is job role/department. Layoffs and union membership are definitely not evenly distributed across role/department, but there is not enough info in the article to know if the layoffs were targeting specific roles or uniform across the company.