The quarterly client newsletter from Perkins Capital Management was eagerly anticipated because, from an exchange of email, it was clear that founder and patriarch Richard “Perk” Perkins was going to address the Medtronic-Covidien tax inversion deal.

The transaction, a stock and cash deal that valued Covidien at over $93 per share, is also taxable for shareholders of both companies. This was a surprise to many longtime Medtronic shareholders, including Perkins, who have seen Medtronic acquire numerous companies before with no such tax.

The tax savings and balance sheet flexibility to be achieved by relocating to Ireland “all sounds great at first blush, and maybe it is in terms of creating long-term value, but it gives many Medtronic shareholders apoplexy in the form of a large tax bite, because the exchange of Medtronic shares for new Medtronic PLC shares is a taxable event,” he wrote.

“This is especially hard for Minnesota shareholders as Minnesota does not distinguish between long-term and short-term gains and, worse, all capital gains are the same as ordinary income for tax purposes. Therefore, a Minnesota resident could pay as much as 30 percent in combined federal and state tax on this exchange.”

The interesting thing here is a Perkins does not blame the company’s management or board for creating this taxable event, as the case for going ahead with a corporate inversion is such a strong one.

In this newsletter, he reprinted a chart produced by the Tax Foundation that ranked all 34 nations in the Organization for Economic Co-operation and Development by statutory corporate income tax rate.

At the top, at 12.5 percent, is Ireland, one day soon the home of Medtronic PLC. At the very bottom is the United States, with the highest corporate income tax rate of over 39 percent, considering also the effect of state taxes.

The average rate is 25 percent, and many of the countries with below average rates are less wealthy and so the effort by their policy makers to attract and retain businesses is at least understandable.

It’s also striking to see countries like Sweden and the United Kingdom, which are perceived to be high tax places, charging not only far less than the U.S. but also below the average of all these countries.

Unless and until Congress acts to lower the relative U.S. corporate income tax rate, Perkins wrote, expect the corporate inversions to continue.