Another important characteristic of Belgian national politics is the highly federal nature of decision making. Important decisions require both a national majority (2/3 for constitutional changes), as well as majorities in the two main language groups. On top of that, both these communities can activate 'alarm bell'-procedures, delaying changes. In addition, there are no national parties to speak of. As a result of this, Belgian decision making can be slow and expensive. On top, it tends to significantly favour the more conservative parties. Given the historically very high public expenditure, and the very strict central control over taxation, even for revenues going to regions and communities, the tendency of Belgian governments to lower taxation and especially labour charges has been limited, at least if compared to radical-liberal approaches followed by certain other countries.