The shoal of fish is the model in studies of democracy

Fish move in two or three dimensions - up and down, left and right. Countries also move through a number of dimensions, though these comprise of economic growth, democracy, and infant mortality.

The idea of analysing human social systems based on group behaviour in animals has long interested David Sumpter at the Department of Mathematics. He has previously studied and mathematically formulated how individual animals take after the movement patterns of groups. Yet he and his research colleagues recently published a report in which social movements were described and predicted with the help of differential equations, based on studies of shoals of fish.

‘Fish move in two or three dimensions, which are a part of a human’s conception of up and down, left and right,’ says David Sumpter. `But countries also move through a number of dimensions, though these comprise of economic growth, democracy, and infant mortality. These movements can be described using the same mathematical methods.´

He has collected the material from research projects at Sydney University in Australia over the past five years. Mathematical models have been based on colleagues' biology experiments with ants, grasshoppers and fish. The idea for the current study came three years ago. The source of inspiration was Professor Hans Rosling's Gapminder company and their creative computer simulations of development trends.

‘I had developed methods based on a shoal of fish, but somewhere in the background there was always a desire to model humans. I asked myself whether I could use this type of method on other questions to study, for example, development and social behaviour in humans,’ says David Sumpter.

He contacted Peter Hedstrom at the Institute for Futures Studies in Stockholm, who arranged another partner in the World Value Survey. The project really took off when the World Bank opened its databases as well as the financial support from the Swedish Research Council and the Riksbank. In December, David Sumpter and his colleagues' research findings were presented in the online publication PLoS One. At the same time, they made a video with moving illustrations of 74 countries’ democratic and economic growth since 1981.

‘For example, the democratic criteria is not just about whether the country holds democratic elections. The experts who evaluated democracy and human rights in these countries have taken into account many aspects and then gave the countries values between 0 and 1. We then used the mathematical models that corresponded the best with the development pattern,’ says David Sumpter.

Mainly it's a question of using the countries that have developed democracy in the last 30 years in order to make assumptions about the future for others who find themselves in the same position today. Interest among politicians is large, and several social projects are in the pipeline.

‘In one project we will try to collect data from Sweden’s municipalities and county councils about the link between mental illness and the background of pupils. In another with Institute for Futures Studies, we will study segregation in schools and residential areas, how it has changed over time and what factors lie behind the changes.´

Data from Statistics Sweden will be delayed however; one reason seems to be limited personnel resources. Another is the ethical component that deals with the distribution of information, and to whom, says David Sumpter. Something he anticipates are reactions to the models and questions about how the results should be interpreted.

‘It is no good if we say that this will happen in five years' time and it does not happen. Yet if it is foreseeable, then I think the information is interesting and valuable to pass on. However, the Lucas critique in economics argues that a model that can predict the future can be used to change the model. Accordingly, there is a risk that we actually change society so that what we predicted does not occur.´

‘But if we succeed in changing it for the better, nobody is going to complain that our model was wrong. Imagine if democracy increases in the world because someone has looked at the model and actually changed the strategy to spread democracy?’