The plague had large scale social and economic effects, many of which are recorded in the introduction of the Decameron. People abandoned their friends and family, fled cities, and shut themselves off from the world. Funeral rites became perfunctory or stopped altogether, and work ceased being done. Some felt that the wrath of God was descending upon man, and so fought the plague with prayer. Some felt that they should obey the maxim, "Eat, drink, and be merry, for tomorrow you may die." The society experienced an upheaval to an extent usually only seen in controlled circumstances such as carnival. Faith in religion decreased after the plague, both because of the death of so many of the clergy and because of the failure of prayer to prevent sickness and death.
The economy underwent abrupt and extreme inflation. Since it was so difficult (and dangerous) to procure goods through trade and to produce them, the prices of both goods produced locally and those imported from afar skyrocketed. Because of illness and death workers became exceedingly scarce, so even peasants felt the effects of the new rise in wages. The demand for people to work the land was so high that it threatened the manorial holdings. Serfs were no longer tied to one master; if one left the land, another lord would instantly hire them. The lords had to make changes in order to make the situation more profitable for the peasants and so keep them on their land. In general, wages outpaced prices and the standard of living was subsequently raised.
As a consequence of the beginning of blurring financial distinctions, social distinctions sharpened. The fashions of the nobility became more extravagant in order to emphasize the social standing of the person wearing the clothing. The peasants became slightly more empowered, and revolted when the aristocracy attempted to resist the changes brought about by the plague. In 1358, the peasantry of northern France rioted, and in 1378 disenfranchised guild members revolted. The social and economic structure of Europe was drastically and irretrievably changed.
(Ed: D.S.) Courie, Leonard W. The Black Death and Peasant's Revolt. New York: Wayland Publishers, 1972; Strayer, Joseph R., ed. Dictionary of the Middle Ages. New York: Charles Scribner's Sons. Vol. 2. pp. 257-267.