Michael T. Hannan


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Research

This page describes my research interests over the years, as well as my main current projects.


Topics over time

My 1970 Ph.D. thesis addressed issues of implications of choice of levels of analysis in sociological research. A slightly revised version appeared as Aggregation and Disaggregation in Sociology. (Heath Lexington 1971; revised edition 1985). Subsequent research on this topic with L. Burstein can be found in Estimation from grouped observations (Am. Soc. Rev. 1974).

In the 1970s, I began to conduct theoretical and empirical research on long-term change in populations of organizations. J. Freeman and I initiated a line of work called organizational ecology in The population ecology of organizations (Am. J. Soc. 1977). This topic became the main focus of my research during the 1980s and 90s.

This work has five main strands:

  • Inertia and change: A central premise of organizational ecology is that organizations face strong inertial pressures on their core features which makes selection a prime motor of population change. J. Freeman and I derived this premise as a theorem in an evolutionary argument in Structural inertia and organizational change (Am. Soc. Rev. 1984). This framework continues to guide my research.

  • Emergence of organizational forms: The focal objects in organizational ecology are populations of organizations, defined in terms of organizational forms. Understanding long-term evolution in the world of organizations requires an understanding of the processes by which forms emerge and disappear. Freeman and I took a first stab at addressing these issues in Where do organizational forms come from? (Soc. Forum 1986). The issues raised in this analysis figure prominently in the current wave of research on categories in markets (see below).

  • Age dependence: An effort to integrate organizational demography into the ecological research program investigated how the hazard of organizational mortality varies with age. Freeman, Carroll, and Hannan, The liability of newness (Am. Soc. Rev. 1983) found that the hazard declines with age. A large number of replications found this pattern. However, Barron, West, and Hannan, A time to grow and a time to die (Am. J. Soc. 1994) showed that controlling for age-varying organizational size reverses the pattern.

  • Niche width: Freeman and I developed an evolutionary model for organizational niche width (the dynamic tradeoff between specializing versus generalizing in exploiting the resource environment Niche width and the dynamics of organizational populations (Am. J. Soc. 1983). Later developments saw this model integrated with a model of status processes, in Podolny, Stuart, and Hannan, Networks, knowledge and niches (Am. J. Soc. 1996), and with organizational change, in Dobrev, Kim, and Hannan, Dynamics of niche width and resource partitioning (Am. J. Soc. 2001).

  • Density dependence. The most extensive line of work involved a model that integrates core elements of organizational ecology and neo-institutionalism. The model I developed in 1986 (Tech report 86-6, Cornell Sociology) derives testable implications for the effects of the number of organizations in a population (density) on rates of founding and failure; see Theoretical and methodological issues in the analysis of density-dependent legitimation. (Soc. Methodology 1991). Much research developed to test these implications. The theory and early lines of empirical tests are presented in Hannan & Carroll, Dynamics of Organizational Populations (Oxford Univ. Press 1992). A subsequent extension to multi-level contexts appeared in Hannan, Carroll, Dundon & Torres. Organizational evolution in a multinational context (Am. Soc. Rev. 1994)

The early stage of the general program arising from all this is summarized in Hannan & Freeman Organizational Ecology (Harvard Univ. Press 1989). During the 1990s, I engaged in many collaborative projects that tested implications of theories of organizational ecology. These studies examined diverse populations over long time periods, including automobile manufacturers, banks, credit unions, labor unions, life insurers, newspapers, restaurants, and semiconductor manufacturers. An overview of this work can be found in Carroll & Hannan The Demography of Organizations and Industries (Princeton Univ. Press 2000).

A related empirical project, the Stanford Project on Emerging Companies (SPEC), used extensive interviews and archival data to study the early evolution of a sample of nearly 200 high-tech companies in Silicon Valley. A summary of the most important conclusion of that research— that change in the premises underlying the employment relationship seriously disrupted firms and increased the hazard of failure—can be found in Baron, Hannan, & Burton, Labor pains: change in organizational models and employee turnover in young, high-tech firms (Am. J. Soc. 2001) and Hannan, Baron, Hsu, Koçak, Organizational identities and the hazard of change (Indus. & Corp. Change 2006) .

I also continued my early methodological focus, especially on development of models and methods for analyzing processes of social change. This work deals with analysis of event histories (sample paths of changes in discrete variables) and of panel data on quantitative variables. This work is summarized in Hannan & Tuma, Methods for temporal analysis (Ann. Rev. Soc. 1979), Tuman Hannan & Groneveld Dynamic analysis of event histories (Am. J. Soc. 1979), and Tuma & Hannan, Social Dynamics: Models and Methods, (Academic Press 1984).

Extensive use of these methods was the main focus of my research (with Tuma and Groenveld) in a very large social experiment: The Seattle-Denver Income Maintenance Experiment (SIME/DIME). We learned that income guarantees destabilized marriages overall, but that the most generous programs did not. We developed and estimated a model of income and independence effects that can explain this pattern: Income and marital events (Am. J. Soc. 1977); Income and independence effects on marital dissolution (Am. J. Soc. 1978); A reassessment of the effect of income maintenance on marital dissolution (Am. J. Soc. 1990).


Main current themes

From 2000 onward,  the center of gravity of my work has moved back to theory with increasing emphasis on formalization. Some of this work re-examines the older strands using more refined theoretical languages and seeks to integrate the theory fragments. Much of the newer work concentrates on the structuring effects of categories in markets. An overview of this work as of 2007 can be found in Hannan, Pólos, and Carroll, Logics of Organization Theory: Audiences, Codes, and Ecologies. (Princeton Univ. Press 2007).


Niche theory


Organizational change


Audiences, categories, and forms


Formal languages for sociological theory


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