While it is possible that European politicians have a genetic predisposition for statist policies, I've never thought this is why they support tax harmonization. Self interest is a far more reasonable answer. More specifically, European nations generally have high fiscal burdens. For instance, government spending consumes nearly half of economic output in EU countries, compared to one-third of GDP in the United States.
Not surprisingly, this translates into a higher tax burden, which means jobs and investment generally flee Europe. Tax harmonization is an attempt to stop labor and capital from escaping by creating, for all intents and purposes, a "fiscal fence." But European politicians also want to undermine tax competition because they know the situation is going to get worse. According to a new report, demographic changes almost certainly are going to result in an even bigger welfare state in the future. This means increasingly harsh tax rates on the remaining productive people - which means politicians will try even harder to prevent taxpayers from escaping. The EU Observer reports on the key statistic that is causing angst for Europe's political class:
According to demographic predictions, the EU's population will not only shrink by almost 20 million people by 2050, but its make-up will also change dramatically. While there are currently about four working people of working age for each person of pension age in the EU's 27 member states, there will be fewer than two people to support every elderly person by 2050, with the population gradually ageing.