The most fruitful empirical studies of organizational ecology to date have used data on populations of firms producing newspapers. Studies by Car- roll and Delacroix (1982) and Delacroix and Carroll (1983) analyzed data on such populations in Argentina and Ireland in the nineteenth and twentieth centuries. Carroll (1987) analyzed populations over similarly long periods in seven SMSAs in the United States, and Amburgey, Lehisalo, and Kelly (1988) have conducted similar research on the Finnish population. Although these studies have treated age dependence, rate dependence, niche width, and a variety of other ecological processes, they have not yet considered processes of density dependence, which play a central role in our scheme. Therefore, we collaborated with Glenn Carroll in reanalyzing his data on the population of newspapers in the San Francisco Bay area. What follows is a brief sketch of Carroll’s research design (full details can be found in Carroll 1987).
The first task was to develop a definition of a newspaper that makes sense for the full historical period. This means distinguishing early newspapers from newsletters, pamphlets, and corantos and later newspapers from journals and magazines. Carroll defines a newspaper as a periodical printed by mechanical means, which appeals to those with common literacy, whose contents consist of timely information, and whose publication is directed to a geographically delimited market of consumers and advertisers.
The unit of observation is a newspaper publishing firm. The initiation of a firm is defined in terms of the beginning of publication. The ending of a firm consists of disbanding, absorption by another firm, or equal-status merger that produces a new firm. These three events are considered jointly as mortality. In the case where a publisher produced more than one news- paper, the earliest and last dates of its publishing operations mark the beginning and end of its history.
Ecological analysis of newspaper publishing firms is attractive because good data on even small and short-lived firms are available over long historical periods. The availability of such data reflects the fact that news- paper publication leaves dated material products of direct interest to histo- rians who have catalogued their publishing histories. In addition, publica- tions directed at advertisers have been published yearly for almost the entire history of the industry in the United States. Records on the histories of newspaper publishing firms were collected from the following archival sources: Gregory (1937) for the period 1821-1869, Rowell (various years) for the period 1869-1880, and Ayer (various years) for the period 1881— 1980. In the case of the San Francisco Bay Area, these histories were supplemented by records from special studies by Daggett (1939) and Wheeler (1973).
The San Francisco Bay area (San Francisco, Oakland, and San Jose) is by far the largest of the SMS As included in Carroll’s study. It contains enough variation in density and vital rates to sustain an analysis of the effects of density on such rates. The earliest newspapers in this area began in the 1840s. Over the ensuing 140 years, 2,168 publishing firms have produced newspapers in this area.
Source: Hannan Michael T., Freeman John (1993), Organizational Ecology, Harvard University Press; Reprint edition.