The Black Death was a pandemic that killed up to 200 million people in Europe during the fourteenth century. Its economic impacts were enormous.

The immediate effect was a sharp downturn in agricultural production as a result of loss of labor. This, in turn, prompted widespread famine.

Not all impacts were necessarily negative, however. A shortage of labor for agricultural production, created by the large death toll, generated upward pressure on wages. Peasants were able to demand more for their work, which resulted in—at least temporarily—a better distribution of wealth. In England, one response to this growing demand for higher wages was the Statute of Laborers of 1351. The new ordinance set out that every healthy unemployed person of working age must accept any job offered to him and could not demand wages beyond those that were offered. This met with varying degrees of success.

The Black Death was quite disastrous to Western Europe. Much of the labor supply died out and many more fled to less populated areas. Many fields became overgrown because of the labor shortage. Cities also suffered. Trading centers such as Venice were especially hard hit as they received the initial plague outbreaks. The plague also led to fear—many groups with trading ties in the Middle East such as Jews and Muslims were punished for the plague even though they had nothing to do with the pestilence.

The survivors of the plague had greater opportunities. Less laborers meant that lords had to entice their workers to stay. Some laborers also became landowners. The end of the first plague cycle brought more prosperity for the survivors as goods and food were cheaper than they had been before the plague. Craftsmen could also charge more for their services as there were less of them to go around. The plague was disastrous to Europe as a whole, but the people who survived benefited in the long-term.

In answering this question, we need to think about both short term and long term effects of the Black Death. 

In the short term, the Black Death was, of course, incredibly destructive for the economy of Western Europe.  The plague killed so many people that the economic life of the continent was completely disrupted.  With peasants dying in large numbers, manors lost some of their agricultural output.  With people in cities dying in large numbers, the output produced by artisans declined and so did trade.  All of these things were very damaging to the economy of Western Europe in the short term.

In the long term, the Black Death helped lead to fundamental changes in the economy of Western Europe.  As peasants died, there came to be many fewer peasants even as the need for labor remained relatively constant.  In economic terms, the demand for labor did not drop much, but the supply of labor did.  This meant that peasants could demand better terms in exchange for their labor.  Because of this, many peasants stopped being servile and instead became free laborers.  Ambitious peasants came to be able to buy their own land and become much more economically secure than ever before.  A similar process made urban workers better off as well.

In short, then, the Black Death caused short term damage to Western European economies and caused the economic systems of the region to change in the long term.