What makes populations stabilize? What makes them fluctuate? Are populations in complex ecosystems more stable than populations in simple ecosystems? In 1973, Robert May addressed these questions in this classic book. May investigated the mathematical roots of population dynamics and argued-counter to most current biological thinking-that complex ecosystems in themselves do not lead to population stability.
The long-term good health of populations depends on the continued stability and
functioning of the biosphere’s ecological and physical systems, often referred to
as life-support systems. We ignore this long-established historical truth at our
peril: yet it is all too easy to overlook this dependency, particularly at a time
when the human species is becoming increasingly urbanized and distanced from
these natural systems.
The analysis is based on a comprehensive data-set covering all limited firms in Sweden
during the period 1997-2005. HGFs are defined as the one percent fastest growing firms in the
population. The population is continuing firms, i.e., firms existing throughout a particular time
period. Firm growth is calculated over three, five and seven years. The total growth of firms is
studied, i.e., the sum of organic and acquired growth.
In general, the correlation between the nine groups of HGFs is low, suggesting that
different firms are included among HGFs depending on definition.