The average laboratory samples a population of 7,300 AmazonMechanical Turk workers 2012-2017

Using capture-recapture analysis we estimate the effective size of the active Amazon Mechanical Turk (MTurk) population
that a typical laboratory can access to be about 7,300 workers. We also estimate that the time taken for half of the workers to
leave the MTurk pool and be replaced is about 7 months. Each laboratory has its own population pool which overlaps, often
extensively, with the hundreds of other laboratories using MTurk. Our estimate is based on a sample of 114,460 completed
sessions from 33,408 unique participants and 689 sessions across seven laboratories in the US, Europe, and Australia from
January 2012 to March 2015.<p>This network project brings together economists, psychologists, computer and complexity scientists from three leading centres for behavioural social science at Nottingham, Warwick and UEA. This group will lead a research programme with two broad objectives: to develop and test cross-disciplinary models of human behaviour and behaviour change; to draw out their implications for the formulation and evaluation of public policy.
Foundational research will focus on three inter-related themes: understanding individual behaviour and behaviour change; understanding social and interactive behaviour; rethinking the foundations of policy analysis.
The project will explore implications of the basic science for policy via a series of applied projects connecting naturally with the three themes. These will include: the determinants of consumer credit behaviour; the formation of social values; strategies for evaluation of policies affecting health and safety.
The research will integrate theoretical perspectives from multiple disciplines and utilise a wide range of complementary methodologies including: theoretical modeling of individuals, groups and complex systems; conceptual analysis; lab and field experiments; analysis of large data sets.
The Network will promote high quality cross-disciplinary research and serve as a policy forum for understanding behaviour and behaviour change.</p>