This is clearly a reductio ad absurdum, but mainline (indebted, null- or negative pro-capita economic growth) European countries will never slash the corporate

This is clearly a reductio ad absurdum, but mainline (indebted, null- or negative pro-capita economic growth) European countries will never slash the corporate tax rate down much further because they cannot afford it. Neoliberal rhetoric aside (keep in mind I'm a pretty orthodox and conservative macro-economist of the monetarist bent) trickle-down economics is clearly inaccurate and the fiscal multiplier is apparently greater than one. There's plenty of distortion in the tax systems of these states already (speaking of my native Italy, far too much bias on taxing income of firms and physical people as opposed to taxing consumption, because the latter is difficult to track because of the sizeable shadow economy, whereas the formers are supposedly easier to asses and monetise), the last thing they want is to suddenly end up relying on untested revenue streams. It's just too radical. Indeed there's a way of seeing this in terms of member states acting as a kind of fiscal cartel, and a couple of the states acting as the perennial defectors of Prisoner's Dilemma fame (cue Luxembourg and a couple others that shall go similarly unnamed). Really, the presence of these fiscal regimes within the EU community is a disgrace. On the other hand, keep in mind that Luxembourg is actually acting in an institutionally legitimate manner, presenting a case to the relevant EU authority instead of strutting its stuff unilaterally. They are going out there and testing the case, and there's a high probability that they will lose and set a strong precedent in their disfavour.