2010 Nobel Prize in economics 2

Over at Marginal Revolution Tyler Cowen has written profiles on each of this year’s winners: Diamond, Mortenson, and Pissarides. Alex Tabarrok sums things up by saying,

The 2010 Nobel Prize awarded to Peter A. Diamond, Dale T. Mortensen, Christopher A. Pissarides can be thought of as a prize for unemployment theory.

A key breakthrough was to realize that the problem was not how to explain unemployment per se but rather how to explain hiring, firing, quits, vacancies and job search and to think of unemployment as the result of all of this underlying microeconomic behavior. Notice that the underlying behavior involves not just workers looking for jobs but also employers looking for workers so explaining unemployment would require a theory of job search, worker search and matching and each aspect of the theory would have to be consistent with every other aspect; i.e. how much workers search depends on how much employers are searching (e.g. advertising) and vice-versa and also on the quality of matching and all of these considerations need to be addressed together. It was Mortensen and Pissarides in particular, building on work by Diamond, who built just such a consistent model.

A very surprising empirical fact helped to motivate this perspective: even in a recession millions of jobs are being created every month. The figures we usually hear about the number of jobs created is the net figure but in the United States in August, for example, there were 4.1 million hires (and 4.2 million separations). Thus, as noted above, understanding unemployment requires understanding these much larger flows of job creation and destruction.

The Press Release from The Royal Swedish Academy of Sciences reads,

Markets with search costs

Why are so many people unemployed at the same time that there are a large number of job openings? How can economic policy affect unemployment? This year's Laureates have developed a theory which can be used to answer these questions. This theory is also applicable to markets other than the labor market.

On many markets, buyers and sellers do not always make contact with one another immediately. This concerns, for example, employers who are looking for employees and workers who are trying to find jobs. Since the search process requires time and resources, it creates frictions in the market. On such search markets, the demands of some buyers will not be met, while some sellers cannot sell as much as they would wish. Simultaneously, there are both job vacancies and unemployment on the labor market.

This year's three Laureates have formulated a theoretical framework for search markets. Peter Diamond has analyzed the foundations of search markets. Dale Mortensen and Christopher Pissarides have expanded the theory and have applied it to the labor market. The Laureates' models help us understand the ways in which unemployment, job vacancies, and wages are affected by regulation and economic policy. This may refer to benefit levels in unemployment insurance or rules in regard to hiring and firing. One conclusion is that more generous unemployment benefits give rise to higher unemployment and longer search times.

Search theory has been applied to many other areas in addition to the labor market. This includes, in particular, the housing market. The number of homes for sale varies over time, as does the time it takes for a house to find a buyer and the parties to agree on the price. Search theory has also been used to study questions related to monetary theory, public economics, financial economics, regional economics, and family economics.

Additional information is available here and here.