It what might be considered bad news for health insurers and consumers, pharmaceutical giants Pfizer Inc. and Allergan just announced a $160-billion merger that would create the world’s largest drugmaker with high-profile products such as Botox, Lipitor and Viagra, while increasing pressure on Washington policymakers to address corporate tax policy because the deal would shelter the new firm’s global earnings. Although New York-based Pfizer is the larger company, the deal is structured so that Allergan technically is the purchaser.

The Los Angeles Times reports that the move allows the new firm – which would take Pfizer’s name and be headed by its current chief executive, Ian Read – to be headquartered for tax purposes in Dublin, Ireland, where Allergan already is located, to take advantage of that nation’s lower corporate tax rate. The tactic, known as an inversion, would lead to an effective tax rate for the new company of about 17% to 18%, Pfizer and Allergan said Monday. Pfizer’s effective tax rate last year was about 27%. The new firm would have its global headquarters in New York, but its principal executive offices would be in Ireland, which has a 12.5% corporate tax rate. The U.S. has a 35% corporate tax rate, the highest of any developed economy.

Corporate mergers and acquisitions this year are on pace to break the record of $4.6 trillion set in 2007, according to Dealogic, which tracks the market. Healthcare, in particular, has seen a spree of takeovers as providers, insurers, pharmaceutical makers and drugstores reposition themselves for industry changes spawned by the federal Affordable Care Act.

But critics have raised concerns about the increased number of takeovers. In the case of healthcare, some have said that as the number of players in each sector shrinks, consumers will have fewer choices and prices will rise. The Pfizer-Allergan deal drew such criticism amid the ongoing debate about higher drug prices.