Can't say having a competitive tax rate doesn't bring jobs!
Apple's planned data centre is 166,000 m². That gives us a figure of ~210 jobs for this data centre. But that's based on a figure from four years ago, and given how aggressively companies have pursued automation and on-site staff reduction in data centres, it's likely that the 2015 figure is lower. Maybe a lot lower.
[1] http://www.quora.com/What-is-the-employment-density-of-a-ser...
http://www.nytimes.com/2014/10/20/opinion/ireland-still-addi... http://www.irishtimes.com/news/politics/abolition-of-double-...
This got announced at the last government budget - I could not make any claims about the economic repercussions one way or the other.