Yannis M. Ioannides
- Published in print:
- 2012
- Published Online:
- October 2017
- ISBN:
- 9780691126852
- eISBN:
- 9781400845385
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691126852.003.0008
- Subject:
- Economics and Finance, Development, Growth, and Environmental
This chapter examines the empirics of urban structure and evolution. It first considers Zipf's law for cities and the vibrant exchanges both over theory and empirics pertaining to it. It then ...
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This chapter examines the empirics of urban structure and evolution. It first considers Zipf's law for cities and the vibrant exchanges both over theory and empirics pertaining to it. It then discusses the Duranton model that explains three empirical regularities regarding endogenous city formation: a stationary law for city size distributions that is skewed to the right; churning of industries across cities as cities experience rapid changes in their industrial compositions; and the pattern of urban size transitions. The chapter also explores the empirics of urban transitions by focusing on models of urban evolution that allow for general intradistributional dependence; the hierarchy principle of industrial diversity; the link between geography and spatial clustering; and studies of urban structure based on “quasi-natural experiments.” Finally, it assesses global aspects of city size distribution and its evolution.Less
This chapter examines the empirics of urban structure and evolution. It first considers Zipf's law for cities and the vibrant exchanges both over theory and empirics pertaining to it. It then discusses the Duranton model that explains three empirical regularities regarding endogenous city formation: a stationary law for city size distributions that is skewed to the right; churning of industries across cities as cities experience rapid changes in their industrial compositions; and the pattern of urban size transitions. The chapter also explores the empirics of urban transitions by focusing on models of urban evolution that allow for general intradistributional dependence; the hierarchy principle of industrial diversity; the link between geography and spatial clustering; and studies of urban structure based on “quasi-natural experiments.” Finally, it assesses global aspects of city size distribution and its evolution.
Rein Taagepera
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780199287741
- eISBN:
- 9780191713408
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199287741.001.0001
- Subject:
- Political Science, Democratization
For a given electoral system, what average number and size distribution of parties can we expect? This book makes specific predictions that agree with world averages. The basic factors are assembly ...
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For a given electoral system, what average number and size distribution of parties can we expect? This book makes specific predictions that agree with world averages. The basic factors are assembly size and district magnitude (the number of seats allocated in the district). While previous models tell us only the direction in which to change the electoral system, the present ones also tell us by how much they must be changed so as to obtain the desired change in party system and cabinet duration. These are quantitatively predictive logical models. Combined with known particularities of a country, these models can be used for informed institutional design. Allocation of seats among countries in the European Parliament is also put on a logical basis.Less
For a given electoral system, what average number and size distribution of parties can we expect? This book makes specific predictions that agree with world averages. The basic factors are assembly size and district magnitude (the number of seats allocated in the district). While previous models tell us only the direction in which to change the electoral system, the present ones also tell us by how much they must be changed so as to obtain the desired change in party system and cabinet duration. These are quantitatively predictive logical models. Combined with known particularities of a country, these models can be used for informed institutional design. Allocation of seats among countries in the European Parliament is also put on a logical basis.
Rein Taagepera
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780199287741
- eISBN:
- 9780191713408
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199287741.003.0001
- Subject:
- Political Science, Democratization
An electoral system helps determine the number and size distribution of parties in a country, as well as cabinet duration. Electoral systems are expressed in electoral laws. Their impact depends on ...
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An electoral system helps determine the number and size distribution of parties in a country, as well as cabinet duration. Electoral systems are expressed in electoral laws. Their impact depends on the way politicians and voters make use of these laws. Flawed electoral laws can lead to breakdown of democracy or to staleness.Less
An electoral system helps determine the number and size distribution of parties in a country, as well as cabinet duration. Electoral systems are expressed in electoral laws. Their impact depends on the way politicians and voters make use of these laws. Flawed electoral laws can lead to breakdown of democracy or to staleness.
S. K. Morgan Ernest
- Published in print:
- 2013
- Published Online:
- January 2014
- ISBN:
- 9780226012148
- eISBN:
- 9780226012285
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226012285.003.0007
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter examines the evidence demonstrating the role body size plays in mammal communities; discusses the important insights that can be obtained by broadening the mammalian research agenda to ...
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This chapter examines the evidence demonstrating the role body size plays in mammal communities; discusses the important insights that can be obtained by broadening the mammalian research agenda to include the use of individual-level body size distributions; and examines the potential benefits of simultaneously exploring and comparing the relationships between individual and species-level body size distributions using data from nine small mammal communities. The highly conserved nature of species size distributions suggests that this distribution may be a fundamental aspect of how mammals assemble, regardless of habitat type or species composition. In contrast, the sensitivity of the body size energy distribution to shifting species composition suggests that the shape of individual-based distributions may be more context specific.Less
This chapter examines the evidence demonstrating the role body size plays in mammal communities; discusses the important insights that can be obtained by broadening the mammalian research agenda to include the use of individual-level body size distributions; and examines the potential benefits of simultaneously exploring and comparing the relationships between individual and species-level body size distributions using data from nine small mammal communities. The highly conserved nature of species size distributions suggests that this distribution may be a fundamental aspect of how mammals assemble, regardless of habitat type or species composition. In contrast, the sensitivity of the body size energy distribution to shifting species composition suggests that the shape of individual-based distributions may be more context specific.
S. Kathleen Lyons and Felisa A. Smith
- Published in print:
- 2013
- Published Online:
- January 2014
- ISBN:
- 9780226012148
- eISBN:
- 9780226012285
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226012285.003.0006
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter examines the macroecological patterns of body size in mammals across space and time. It addresses the following questions: How similar are overall body size distributions across ...
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This chapter examines the macroecological patterns of body size in mammals across space and time. It addresses the following questions: How similar are overall body size distributions across individual continents and large islands? How similar are overall body size distributions across time in North America? Are present-day patterns warped? Is the relationship between body size and range size consistent across time and space? Are the shapes of body size distributions at the community level consistent across time and space? The results show gross similarities in macroecological patterns across land masses and throughout evolutionary time. Although there are unique aspects to the patterns on individual continents, the shapes of body size distributions and the moments of the distributions are remarkably similar despite their different evolutionary and geological histories.Less
This chapter examines the macroecological patterns of body size in mammals across space and time. It addresses the following questions: How similar are overall body size distributions across individual continents and large islands? How similar are overall body size distributions across time in North America? Are present-day patterns warped? Is the relationship between body size and range size consistent across time and space? Are the shapes of body size distributions at the community level consistent across time and space? The results show gross similarities in macroecological patterns across land masses and throughout evolutionary time. Although there are unique aspects to the patterns on individual continents, the shapes of body size distributions and the moments of the distributions are remarkably similar despite their different evolutionary and geological histories.
Louis W. Botsford, J. Wilson White, and Alan Hastings
- Published in print:
- 2019
- Published Online:
- November 2019
- ISBN:
- 9780198758365
- eISBN:
- 9780191818301
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198758365.003.0005
- Subject:
- Biology, Biodiversity / Conservation Biology, Biomathematics / Statistics and Data Analysis / Complexity Studies
This chapter begins by revisiting the M’Kendrick/von Foerster model, but using size instead of age as the state variable. It then uses the lessons from that model to describe how individual growth ...
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This chapter begins by revisiting the M’Kendrick/von Foerster model, but using size instead of age as the state variable. It then uses the lessons from that model to describe how individual growth and mortality rates determine both stand distributions (a population of mixed ages) and cohort distributions (all one age). In particular, incorporating variability in growth trajectories is shown to be important in obtaining realistic results—though it is not without pitfalls. Ultimately, the numerical calculations required to model size-structured populations for future projections are more challenging than those needed for age structure, so the chapter closes by discussing some mathematical tools that have been developed to accomplish this. These include the integral projection model, a recent approach that is very useful because, while more complex, it has a lot in common with the age-structured models examined in Chapters 3 and 4.Less
This chapter begins by revisiting the M’Kendrick/von Foerster model, but using size instead of age as the state variable. It then uses the lessons from that model to describe how individual growth and mortality rates determine both stand distributions (a population of mixed ages) and cohort distributions (all one age). In particular, incorporating variability in growth trajectories is shown to be important in obtaining realistic results—though it is not without pitfalls. Ultimately, the numerical calculations required to model size-structured populations for future projections are more challenging than those needed for age structure, so the chapter closes by discussing some mathematical tools that have been developed to accomplish this. These include the integral projection model, a recent approach that is very useful because, while more complex, it has a lot in common with the age-structured models examined in Chapters 3 and 4.
John Harte
- Published in print:
- 2011
- Published Online:
- December 2013
- ISBN:
- 9780199593415
- eISBN:
- 9780191774614
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199593415.001.0001
- Subject:
- Biology, Ecology
A goal of every science is comprehensive theory that is predictive, realistic, and parsimonious. Is such theory possible in ecology? The sheer complexity, historical contingency, and scale-dependence ...
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A goal of every science is comprehensive theory that is predictive, realistic, and parsimonious. Is such theory possible in ecology? The sheer complexity, historical contingency, and scale-dependence of organisms and their interactions with their surroundings suggest to many a negative answer. This book answers yes. Rather than building and combining mechanistic models of ecosystems, the approach here is grounded in information theory and the logic of inference. Paralleling the derivation of thermodynamics from the maximum entropy principle, the state variable theory of ecology developed in the book predicts realistic forms for all metrics of ecology that describe patterns in the distribution, abundance, and energetics of species across multiple spatial scales. Part I is foundational, discussing the nature of theory, the relationship of ecology to other sciences, and the concept of the logic of inference. Parts II and III, respectively, present the fundamentals of macroecology and of maximum information entropy from the ground up. Part IV integrates the fundamentals, leading to the derivation and testing of the predictions of the maximum entropy theory of ecology (METE). Part V widens the perspective by showing how METE can help clarify several major issues in conservation biology, placing METE in context with other theories, and pointing readers along avenues for future research.Less
A goal of every science is comprehensive theory that is predictive, realistic, and parsimonious. Is such theory possible in ecology? The sheer complexity, historical contingency, and scale-dependence of organisms and their interactions with their surroundings suggest to many a negative answer. This book answers yes. Rather than building and combining mechanistic models of ecosystems, the approach here is grounded in information theory and the logic of inference. Paralleling the derivation of thermodynamics from the maximum entropy principle, the state variable theory of ecology developed in the book predicts realistic forms for all metrics of ecology that describe patterns in the distribution, abundance, and energetics of species across multiple spatial scales. Part I is foundational, discussing the nature of theory, the relationship of ecology to other sciences, and the concept of the logic of inference. Parts II and III, respectively, present the fundamentals of macroecology and of maximum information entropy from the ground up. Part IV integrates the fundamentals, leading to the derivation and testing of the predictions of the maximum entropy theory of ecology (METE). Part V widens the perspective by showing how METE can help clarify several major issues in conservation biology, placing METE in context with other theories, and pointing readers along avenues for future research.
Dmitri I. Svergun, Michel H. J. Koch, Peter A. Timmins, and Roland P. May
- Published in print:
- 2013
- Published Online:
- December 2013
- ISBN:
- 9780199639533
- eISBN:
- 9780191747731
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199639533.003.0006
- Subject:
- Physics, Crystallography
Chapter 5 deals with the systems, which deviate from the ideal monodisperse solutions. The most important cases of such systems are (i) solutions of particles differing in size, shape or conformation ...
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Chapter 5 deals with the systems, which deviate from the ideal monodisperse solutions. The most important cases of such systems are (i) solutions of particles differing in size, shape or conformation (such as equilibrium mixtures of oligomers or solutions of flexible macromolecules), and (ii) solutions, where interparticle interactions cannot be neglected (such as concentrated solutions of (charged) particles). The structural analysis procedures for these systems differ from those for monodisperse systems. Indeed, it would make little sense to try to reconstruct the shape or model the structure of a single particle based on the scattering from a mixture or a strongly interacting system. Relevant questions for the characterisation of such systems relate, for example, to the composition of the mixture or the type of interaction potential. The different data-analysis methods employed for polydisperse and interacting systems are considered.Less
Chapter 5 deals with the systems, which deviate from the ideal monodisperse solutions. The most important cases of such systems are (i) solutions of particles differing in size, shape or conformation (such as equilibrium mixtures of oligomers or solutions of flexible macromolecules), and (ii) solutions, where interparticle interactions cannot be neglected (such as concentrated solutions of (charged) particles). The structural analysis procedures for these systems differ from those for monodisperse systems. Indeed, it would make little sense to try to reconstruct the shape or model the structure of a single particle based on the scattering from a mixture or a strongly interacting system. Relevant questions for the characterisation of such systems relate, for example, to the composition of the mixture or the type of interaction potential. The different data-analysis methods employed for polydisperse and interacting systems are considered.
Thomas J. Holmes and Sanghoon Lee (eds)
- Published in print:
- 2010
- Published Online:
- February 2013
- ISBN:
- 9780226297897
- eISBN:
- 9780226297927
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226297927.003.0004
- Subject:
- Economics and Finance, Microeconomics
A question in urban economics that has attracted much attention is the extent to which the size distribution of cities obeys Zipf's law. This chapter considers a new approach to looking at population ...
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A question in urban economics that has attracted much attention is the extent to which the size distribution of cities obeys Zipf's law. This chapter considers a new approach to looking at population distributions that sweeps out any decisions made by bureaucrats or politicians. When comparing populations of geographic units, differences fall along two margins. First, one unit can have a larger population than another because it encompasses a greater land area, holding population density fixed. Second, a unit can have a larger population on a fixed amount of land; that is, higher population density. The chapter analyzes size distribution by cutting the map of the continental United States into a uniform grid of six-by-six-mile squares, and examines the distribution of population across the squares and the extent to which Zipf's law holds for each. A joint analysis of the distribution of population of squares within and across metropolitan areas is a fruitful area for further research.Less
A question in urban economics that has attracted much attention is the extent to which the size distribution of cities obeys Zipf's law. This chapter considers a new approach to looking at population distributions that sweeps out any decisions made by bureaucrats or politicians. When comparing populations of geographic units, differences fall along two margins. First, one unit can have a larger population than another because it encompasses a greater land area, holding population density fixed. Second, a unit can have a larger population on a fixed amount of land; that is, higher population density. The chapter analyzes size distribution by cutting the map of the continental United States into a uniform grid of six-by-six-mile squares, and examines the distribution of population across the squares and the extent to which Zipf's law holds for each. A joint analysis of the distribution of population of squares within and across metropolitan areas is a fruitful area for further research.
Pierre M. Adler, Jean-François Thovert, and Valeri V. Mourzenko
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199666515
- eISBN:
- 9780191748639
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199666515.003.0003
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter deals with the geometry of random networks. The fractures are generally considered as plane objects such as polygons. The most important question relative to these networks is whether ...
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This chapter deals with the geometry of random networks. The fractures are generally considered as plane objects such as polygons. The most important question relative to these networks is whether they percolate or not. In simple terms, can a Maxwell demon or the like go through the whole medium by walking on the fractures without any jump? The concept of percolation is detailed and applied to fracture networks in conjunction with the excluded volume. The dimensionless density is defined as the number of fractures per excluded volume and is shown to control percolation; this quantity is crucial since it plays a major role in the permeability of fracture networks and of fractured porous media as well. Then, the dimensionless density is estimated from data which can be measured along lines (wells, outcrops,...) or on surfaces (quarries, outcrops,...). This chapter ends with extensions such as fractures with power law size distributions and anisotropic orientations.Less
This chapter deals with the geometry of random networks. The fractures are generally considered as plane objects such as polygons. The most important question relative to these networks is whether they percolate or not. In simple terms, can a Maxwell demon or the like go through the whole medium by walking on the fractures without any jump? The concept of percolation is detailed and applied to fracture networks in conjunction with the excluded volume. The dimensionless density is defined as the number of fractures per excluded volume and is shown to control percolation; this quantity is crucial since it plays a major role in the permeability of fracture networks and of fractured porous media as well. Then, the dimensionless density is estimated from data which can be measured along lines (wells, outcrops,...) or on surfaces (quarries, outcrops,...). This chapter ends with extensions such as fractures with power law size distributions and anisotropic orientations.
Felisa A. Smith and S. Kathleen Lyons
- Published in print:
- 2013
- Published Online:
- January 2014
- ISBN:
- 9780226012148
- eISBN:
- 9780226012285
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226012285.003.0011
- Subject:
- Biology, Evolutionary Biology / Genetics
This chapter begins by summarizing the book's main themes. First, we can now begin to appreciate just how much variation there is in body size among most groups of animals. Second, there are ...
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This chapter begins by summarizing the book's main themes. First, we can now begin to appreciate just how much variation there is in body size among most groups of animals. Second, there are remarkably consistent patterns in the body size distributions of some taxa across spatial and temporal gradients that may well reflect how organisms acquire and allocate energy. Third, temperature is important. The discussion then turns to the gaps in this compilation, such as the exclusive focus on animals and the lack of detailed species-level phylogeny for most groups, which hampers the ability to examine the influence of evolutionary history on the body size patterns of animals.Less
This chapter begins by summarizing the book's main themes. First, we can now begin to appreciate just how much variation there is in body size among most groups of animals. Second, there are remarkably consistent patterns in the body size distributions of some taxa across spatial and temporal gradients that may well reflect how organisms acquire and allocate energy. Third, temperature is important. The discussion then turns to the gaps in this compilation, such as the exclusive focus on animals and the lack of detailed species-level phylogeny for most groups, which hampers the ability to examine the influence of evolutionary history on the body size patterns of animals.
Walter Steurer and Julia Dshemuchadse
- Published in print:
- 2016
- Published Online:
- September 2016
- ISBN:
- 9780198714552
- eISBN:
- 9780191782848
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198714552.003.0005
- Subject:
- Physics, Crystallography
In this chapter, a statistical analysis of all structures and structure types of the intermetallic compounds contained in the reduced database “Pearson’s Crystal Data” (PCD) is discussed. The goal is ...
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In this chapter, a statistical analysis of all structures and structure types of the intermetallic compounds contained in the reduced database “Pearson’s Crystal Data” (PCD) is discussed. The goal is to identify, analyze, and discuss structural regularities and relationships for improving one’s understanding of the formation and stability of intermetallics, in order to get a flavor of the big picture. The most important ordering parameters used in this analysis are the Mendeleev numbers. Based on them, the distributions of chemical compositions, stoichiometries, and symmetries of the binary and ternary intermetallic compounds are discussed separately, as well as the occurrence and characteristics of the most common structure types. Also of interest is the distribution of the number of representatives of the structure types, which varies in a wide range.Less
In this chapter, a statistical analysis of all structures and structure types of the intermetallic compounds contained in the reduced database “Pearson’s Crystal Data” (PCD) is discussed. The goal is to identify, analyze, and discuss structural regularities and relationships for improving one’s understanding of the formation and stability of intermetallics, in order to get a flavor of the big picture. The most important ordering parameters used in this analysis are the Mendeleev numbers. Based on them, the distributions of chemical compositions, stoichiometries, and symmetries of the binary and ternary intermetallic compounds are discussed separately, as well as the occurrence and characteristics of the most common structure types. Also of interest is the distribution of the number of representatives of the structure types, which varies in a wide range.
Anne Nédélec and Jean-Luc Bouchez
- Published in print:
- 2015
- Published Online:
- April 2015
- ISBN:
- 9780198705611
- eISBN:
- 9780191774515
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198705611.003.0008
- Subject:
- Physics, Geophysics, Atmospheric and Environmental Physics
Important aspects of magma crystallization are examined in detail, from the formation of the first crystal nuclei and their growth to the fate of the late-magmatic processes, such as residual melts, ...
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Important aspects of magma crystallization are examined in detail, from the formation of the first crystal nuclei and their growth to the fate of the late-magmatic processes, such as residual melts, pegmatites and aplites. Orders of crystallization of minerals are presented with respect to the textural observations under the microscope, and magma compositions. Fractional crystallization is considered and illustrated by considerations about the respective concentrations of compatible and incompatible elements. Finally, Subsolidus mineral transformations due to hydrothermal processes and exsolution are considered. Sections deal with nucleation and crystal growth, including crystal size distributions (CSDs), the order in which minerals crystallize, fractional crystallization and magmatic differentiation, late-magmatic processes, and subsolidus mineral transformations.Less
Important aspects of magma crystallization are examined in detail, from the formation of the first crystal nuclei and their growth to the fate of the late-magmatic processes, such as residual melts, pegmatites and aplites. Orders of crystallization of minerals are presented with respect to the textural observations under the microscope, and magma compositions. Fractional crystallization is considered and illustrated by considerations about the respective concentrations of compatible and incompatible elements. Finally, Subsolidus mineral transformations due to hydrothermal processes and exsolution are considered. Sections deal with nucleation and crystal growth, including crystal size distributions (CSDs), the order in which minerals crystallize, fractional crystallization and magmatic differentiation, late-magmatic processes, and subsolidus mineral transformations.
Roger W. Spencer and David A. Macpherson
- Published in print:
- 2014
- Published Online:
- May 2015
- ISBN:
- 9780262027960
- eISBN:
- 9780262325868
- Item type:
- chapter
- Publisher:
- The MIT Press
- DOI:
- 10.7551/mitpress/9780262027960.003.0009
- Subject:
- Economics and Finance, Economic History
This chapter looks at the work of Robert M. Solow, who was awarded the Nobel Prize in 1987. Solow was born in 1924 and recieved his B.A., M.A., and Ph.D.from Harvard University. He started out ...
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This chapter looks at the work of Robert M. Solow, who was awarded the Nobel Prize in 1987. Solow was born in 1924 and recieved his B.A., M.A., and Ph.D.from Harvard University. He started out serving as assistant and associative professor of statistics. He was then appointed as professor of economics. He progressed to become institute professor and institute professor, emeritus, both at MIT. His doctorate thesis presented a model on the dynamics of the size distribution of incomes as the outcome of a random process of employment in terms of changes in wage levels. He also developed his own version of growth theory encompassing capital-theoretic overtones. Among his titles are Linear Programming and Economic Analysis and Monopolistic Competition and Macroeconomic Theory.Less
This chapter looks at the work of Robert M. Solow, who was awarded the Nobel Prize in 1987. Solow was born in 1924 and recieved his B.A., M.A., and Ph.D.from Harvard University. He started out serving as assistant and associative professor of statistics. He was then appointed as professor of economics. He progressed to become institute professor and institute professor, emeritus, both at MIT. His doctorate thesis presented a model on the dynamics of the size distribution of incomes as the outcome of a random process of employment in terms of changes in wage levels. He also developed his own version of growth theory encompassing capital-theoretic overtones. Among his titles are Linear Programming and Economic Analysis and Monopolistic Competition and Macroeconomic Theory.
