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Paper published in Sociological Methods and Research

posted Jul 20, 2017, 2:46 PM by Michael Maes   [ updated Jul 20, 2017, 2:51 PM ]
Great news. Sociological Methods and Research accepted a joint paper with Dirk Helbing. In this paper, we report results of two experiments testing hypotheses about the effects of noise on the micro-level on macro-outcomes.

While there is no doubt that human behavior follows certain patterns, there is also obvious that humans also often deviate from these patterns. Most social scientists do not pay attention to these deviations. However, many theories predict that deviations from the behavioral patterns of individuals can have decisive impact on the behavior of social collectives even when deviations are rare and random. In this paper, we tested this notion, showing that macro-deviations can have macro-effects and that it can be accurately predicted when deviations matter.

Title: Random deviations improve micro-macro predictions. An empirical test.

Abstract: Many sociological theories make critically different macro-predictions when their micro-assumptions are implemented stochastically rather than deterministically. Deviations from individuals’ behavioral patterns described by micro-theories can spark cascades that change macro-outcomes, even when deviations are rare and random. With two experiments, we empirically tested whether macro-phenomena can be critically shaped by random deviations. 96 percent of participants’ decisions were in line with a deterministic theory of bounded rationality. Despite this impressive micro-level accuracy, the deterministic model failed to predict the observed macro- outcomes. However, a stochastic version of the same micro-theory largely improved macro-predictions. The stochastic model also correctly predicted the conditions under which deviations mattered. Results also supported the hypothesis that non-random deviations can result in fundamentally different macro-outcomes than random deviations. In conclusion, we echo the warning that deterministic micro-theories can be misleading. Our findings show that taking into account deviations in sociological theories can improve explanations and predictions.