Lateral pressure theory assumes that each statistic is an indicator of – and consequence of – a discrete decision by an individual human being governed by his or her preferences. The larger the size of the community the greater is the demands, wants and needs. Population growth, for example, is in fact the outcome of a large number of discrete private decisions (due to volition or to coercion) over which policy makers or national governments are not likely to have direct control. In this connection, if there is any “determinism” in this logic, it is one driven by individual decision.  Indicators of technology, like those of population, are also the observed outcomes of a number of widely dispersed decisions by individual actors such as developers, inventors, scientists, investors, manufacturers, etc. The same holds for resource access and uses. Statistics involve descriptions of and generalizations about aggregates. Empirical analyses of lateral pressure theory have gone through several phases with each phase providing grounds for added developments in theory and new challenges for quantitative analysis.

The earliest studies were completed in the decade of the 1970s. Until very recently the theory dwelt in the physical realm of traditional world politics – along with all other theoretical and empirical analysis in international relations.  The construction of cyberspace created new challenges pertaining to quantification of the master variables, state profiles, and patterns of behavior. This section focuses on empirical theory and analysis in the conventional realm, necessary prerequisite for understanding measures and metrics for the cyber domain.

In retrospect, we now appreciate that our quantitative work and empirically based inferences have evolved over time. We can now point to distinct phases, each with its theoretical and methodological features.

1. Major Power Interactions, 1870-1914
2. Japan Growth and Expansion: 1868-1970
3. Highlighting Complexity
4. Global Environmental Change
5. Sustainable Development