Pfizer, based in New York, already makes an ingredient for Viagra in Cork, in the south of the country, while Allergan produces Botox in Mayo, in the west.
There's little sign of a slowdown in investment in Ireland, even as European regulators probe the state's tax arrangements with Apple and the government distances itself from tax-based transactions which don't produce local jobs.
"We are not pushing for inversions," Irish Finance Minister Michael Noonan told reporters in Brussels on Monday, referring to the controversial transaction meant to cut corporate tax rates. The agency charged with winning investment for Ireland "never promotes inversions. It's a decision for the two companies."
The whole issue here brings more bad publicity on the country, as it is likely to further enhance the notion of Ireland as a tax-haven.
While Noonan said Allergan and Pfizer were plainly merging for "tax advantages," the government has no problem with the deal as both companies had "substantial" operations in Ireland.
Pfizer employs 3,300 people in Ireland and has invested $7 billion in the country since 1969. Allergan employs over 1,000 people in Westport in County Mayo.
In all, 140,000 people are directly employed by over 700 U.S. companies in Ireland, a country of 4.6 million people, according to the American Chamber of Commerce in Ireland. Ireland is the biggest global location worldwide for U.S. foreign direct investment in the chemicals sector, which includes drugs, the organization said. Ireland's pharmaceutical exports are the seventh largest in the world, according to IBEC, a Dublin-based group representing employers.
Yet, not such all deals are welcome. Last year, Noonan said tax inversions by companies not backed by real activities in Ireland can add to a "negative perception" of the government's tax strategy.
It's perfectly sensible to move to a better corporate tax environment.
"I can understand Noonan's apprehension," said Alan McQuaid, an economist at Merrion Capital in Dublin. "The whole issue here brings more bad publicity on the country, as it is likely to further enhance the notion of Ireland as a tax-haven."
Already, European antitrust officials are probing Apple's tax dealings in Ireland, with Noonan saying a ruling will probably be made after Christmas. As criticism of Ireland grew, Noonan is phasing out a controversial loophole known as the "Double Irish," introducing a new lower tax on intellectual property.
And the investment keeps coming. Last month, for example, Barcelona-based Grifols, Europe's largest maker of blood- plasma products, said it would provide 140 jobs in Ireland, and Noonan said on Monday that the government would focus on increasing employment at the new operation formed by the Pfizer and Allergan merger.
"The U.S. doesn't offer a competitive regime. We do," said Fergal O'Brien, head of policy at IBEC. "It's perfectly sensible to move to a better corporate tax environment."