Council of Labour. It would follow that the polder model is much older and therefore could have had a larger influence on Dutch society and economy than has generally been thought up to now. Other uses The term polder model and especially the verb polderen ("to polder") has been used pejoratively by some politicians to describe the slow decision-making process where all parties have to be heard. The model flourished under the purple coalition governments of Prime Minister Wim Kok, a coalition including the traditional rivals the Labour Party (a social-democratic party, whose colour is red) and the People's Party for Freedom and Democracy (right-wing liberals, whose colour is blue). In the declining economic climate of the early 21st century, the model came under fierce attack particularly from right-wing politicians and Pim Fortuyn in his book entitled De puinhopen van acht jaar Paars (The Wreckage of Eight Years Purple'). Historical background There is no consensus about the exact historical background of the polder model. In general, there are three views on this subject. One explanation points to the rebuilding of the Netherlands after World War II. Corporatism was an important feature of Christian democracy and particularly Catholic political thought. During the postwar period, the Catholic, Protestant, Christian, social-democratic, and liberal parties decided to work together to reconstruct the Netherlands, as did labour unions and employers' organizations. Important institutions of the polder model like the SER were founded in this period. No single political party has ever had anything approaching an overall majority in parliament, so a coalition government is inevitable. This makes parties extremely cautious, since today's enemy may be tomorrow's ally, all the more so in present times when the perceived death of ideology has made it possible for almost all the parties to work together. Another explanation points to the dependency of the Netherlands on international trade and the world economy. The Dutch cannot afford protectionism against the unpredictable tides of the international economy because the Netherlands is not an autarkic economy. To cushion against the international economy, they set up the Social-Economic Council, which oversaw an extensive welfare state. A third explanation refers to a unique aspect of the Netherlands, that it consists in large part of polders, land reclaimed from the sea, which requires constant pumping and maintenance of the dykes. Ever since the Middle Ages, when the process of land reclamation began, different societies living