http://en.wikipedia.org/wiki/Consequences_of_the_Black_Death said:
In Western Europe, the sudden shortage of cheap labour provided an incentive for landlords to compete for peasants with wages and freedoms, an innovation that, some argue, represents the roots of capitalism, and the resulting social upheaval "caused" the Renaissance, and even the Reformation. In many ways the Black Death and its aftermath improved the situation of surviving peasants, notably by the end of the 15th century. In Western Europe, labourers gained more power and were more in demand because of the shortage of labour. In gaining more power, workers following the Black Death often moved away from annual contracts in favour of taking on successive temporary jobs that offered higher wages.[22] Workers such as servants now had the opportunity to leave their current employment to seek better-paying, more attractive positions in areas previously off limits to them.[17] Another positive aspect of the period was that there was more fertile land available to the population...
Since it is believed to have in part caused the social upheavals of fourteenth- and fifteenth-century Western Europe, some see the Black Death as a factor in the Renaissance and even the Reformation in Western Europe. Therefore, some historians have cited[citation needed] the smaller impact of the plague as a contributing factor in Eastern Europe's failure to experience either of these movements on a similar scale. Extrapolating from this, the Black Death may be seen as partly responsible for Eastern Europe's considerable lag in the move to liberalise government by restricting the power of the monarch and aristocracy. A common example is that by the mid-sixteenth century, England began the process that ultimately ended serfdom there and gave rise to representative government; meanwhile, Russia did not formally abolish serfdom until an autocratic tsar decreed so in 1861.
Furthermore, the plague's great population reduction brought cheaper land prices, more food for the average peasant, and a relatively large increase in per capita income among the peasantry...
However, the upper class often attempted to stop these changes, initially in Western Europe, and more forcefully and successfully in Eastern Europe, by instituting sumptuary laws. These regulated what people (particularly of the peasant class) could wear, so that nobles could ensure that peasants did not begin to dress and act as a higher class member with their increased wealth.
