Human population facing long wave variability:

an ecological approach

Salvador E. Lluch-Cota

Centro de Investigaciones Biologicas del Noroeste, S.C.

PoBox 128. La Paz, BCS. 2300. Mexico

Salvador Lluch <>

Abstract: It is proposed that long wave economic cycles are related to natural variability, and thus we might only be able to properly manage the ecosystem by combining our understanding of the sources and mechanisms of that natural variability to our limited social and economic planning capabilities.

Keywords: ecology, economic cycles, ecological periodicity, fixed long wave cycles.


Life on earth is limited and controlled by the environment. Biological populations' size and distribution depends primarily on the availability of proper set of conditions such as light, water, temperature, food, predators, competition, etcetera.

Human population facing recurrent patterns

For the human population, limiting factors are becoming less limiting each day. We can feed upon many different resources, beat unfavourable conditions by technological development, inhabit extreme conditions (i.e. cold, hot, poor, dry, wet, etc.), face predators and deleterious organisms, and change the environment to even create and disappear otherwise natural conditions. However, human activity still follows cyclical patterns in response to climatic pressures. Almost every element of our lifestyle is organized under a day/night regime, and variability through the year controls many of our activity (we know there is a summer vacation period, a seeding/harvesting epoch, hunting and fishing seasons, etc.). Understanding this coupling between human life and climate is very strait forward as we know there is a day/night cycle produced by Earth's rotation, and a seasonality resulting from the Earth's orbiting around the sun. Although, it would be very innocent of us to believe that climate only influences us in the annual or shorter time scales but we can hardly identify, let alone realize the impact of the climate in longer-than-annual time scales.

The existence of cyclical patterns in the economic behaviour worldwide is hardly denied nowadays, and simple observation of the many different historical records reveals patterns of variability and recurrent events at quasi fixed long wave interannual-to-decadal time-scales. However, there is no agreement on the driving forces behind those signals.

Nikolai Kondratieff is to be considered the father of economic long waves analyses. By simply applying a 9-year moving average to several production and consumption time series, Kondratieff proposed the existence of waves with duration of 46 to 60 years with an average frequency of 54 years. Basic idea behind Kondratieff theory is that people inflate the economy by consuming more than the productive capacity can meet, thereby when capacity grows, people deflate by consuming less than the available capacity produces [1].

The driving forces behind long wave economic variability is still a matter of debate. For a long time, endogenous factors were considered the main cause but some people did not pass by the fact that there might be important exogenous forcing. Schumpeter's theory is based in scientific-technological changes, not only by key scientific-technological discoveries but as a clustering of innovations over time, however, he did not speculate about what causes the innovations clustering [2]. Other lines of thinking believe that long wave behaviour is caused by fluctuations in the growth rate of the population as noted by the work force.

Still, those approaches that consider the variability as a consequence of human population/society dynamics and natural sources of variability have been poorly considered [3].

The pragmatic economists point of view is that whatever causes this long wave cycles is not the main point, but knowing they exist and consider them for economic planning and analyses. However, an ecological perspective would be to identify the sources of variability, understand and forecast them and provide the knowledge to manage them as we do with the daily and seasonal variability.

Natural long wave variability

Natural long wave variability is hardly denied nowadays. Paleoecological studies have clearly proved several longer-than-seasonal and shorter-than-glacial signals. Some of them are easily detected, such as ENSO, and some others are hard to study because of the limited record period. However, some cases of long wave variability are well documented and some of them are detected in biological populations variability.

One good example is the recognition of non-random naturally induced environmental variability which has major effects on the abundance of fish resources worldwide such as sardine and anchovies in a synchronous manner world wide and in periods of nearly 60 years [4], implying two very important facts: 1) because of synchronies between populations at very separated regions of the world ocean, there must be a global climate link, and 2) regime changes pose severe problems for the sustainability of economic development and actual knowledge within the fisheries science is inadequate for the management of such populations [5].

Possible linkages

Since natural decadal variability exists and affects biological populations, standing crops of the natural stock of resources for human consumption and utilization are also variate. Even with the human capacity of mitigating adverse environmental conditions, low frequency variability in the environmental set of conditions must result in social, cultural, and economic re-adaptation.

Mechanisms linking natural variability and human-related variability at low frequencies must be further analysed as there might be two possible explanations:

a) Economic cycles directly result from the availability of natural resources

b) Economic cycles are the result of human activity driven by the demand of re-adaptation of society.

Understanding the first case is very straight forward, however human society is much more complex than that. The second possibility implies that a well adapted society is specialized in the exploitation and culture of a limited set of resources within a growing technological framework and in tune with people's preferences. Under those conditions, a change in the environment (sudden or gradual shift) results in the necessity of new technology, readjustment of people's preferences, possible changes in the Social Structures of Accumulation, and more.


Humanity can learn from observation to control the environmental variability better then the rest of the species and earlier than evolutionary time-scale. Thus, we have to face the fact that in order to properly manage of our ecosystem, the sole approach of conservation and sustainable development is inadequate as we have to understand the source of variability and the mechanisms in which they affect us. Time has come for economists, ecologists, earth scientists, and space scientists to sit together in order to gain a better understanding of our environment and to learn how to manage the variability that controls us.

 Notes and references

1. Though being the most famous cycle, Kondratieff waves are not the only low frequency cycle. Simon Kuznets identified a 16.5 to 18 year cycles based on demographic factors, Clement Juglar studied the rise and fall in interest rates and found waves of 9 to 11 year cycles, and Joseph Kitchin discovered a 3 to 4 years cycle that apparently explained a stocking/destocking alternance.

2. Dassbach, C.H.A. Entrepreneurial Motivation and the Clustering of Innovations: A Reconsideration of Schumpeter's Theory of the Kondratieff Cycle. Website at

3. W.S. Jevons noted a 11 years cycle while looking at recurrent economic crisis, and speculated about a possible relation with sunspot activity.

4. Lluch-Belda, D. The Interdecadal Climatic Change Signal in the Temperate Large Marine Ecosystems of the Pacific. Sherman, K. And Q. Tang (eds). Large Marine Ecosystems of the Pacific Rim. Blackwell Science. Oxford, England. 27-41pp.

5. Lluch-Belda D., Schwartzlose, R.A., Serra, R., Parrish, R.H., Kawasaky, T., Hedgecock, D. and Crawford, R.M.J. Sardine and anchovy regime fluctuations of abundance in four regions of the world oceans: a workshop report. 1992. Fish. Ocean., 1(4):339-347.

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