36  All speeches are available online at www.bankofengland.co.uk/publications/Pages/speeches/default.aspx  36  References Alfi, V, Cristelli, M, Pietronero, L, and Zaccaria, A (2009), ‘Minimal agent based model for financial markets I’, The European Physical Journal B,67(3), 385-397 Allen, T and Carroll, C (2001), ‘Individual learning about consumption’, NBER Working Paper No 8234 An, G, Mi, Q, Dutta-Moscato, J and Y Vodovotz(2009), ‘Agent-based models in translational systems biology’, Wiley Interdisciplinary Reviews: Systems Biology and Medicine, vol 1, no 2, pp 159–171 Ausk, B J, Gross, T and Srinivasan, S (2006), ‘An agent based model for real-time signaling induced in osteocytic networks by mechanical stimuli’, Journal of biomechanics 3914: 2638-2646 Axelrod (1997), R M Axelrod, ‘The complexity of cooperation: Agent-based models of competition and collaboration’, Princeton University Press Bak, P, Tang, C and Wiesenfeld, K (1988), ‘Self-organized criticality’, Physical review A 38, no 1: 364 Bank of England (2015), ‘One Bank Research Agenda: Discussion Paper’, available at: http://wwwbankofenglandcouk/research/Documents/onebank/discussionpdf Baptista, R, Farmer, J D, Hinterschweiger, M, Low, K, Tang, D and Uluc, A (2016), ‘Macroprudential policy in an agent-based model of the UK housing market’, Bank of England Staff Working Paper No 619 Barabasi, A L (2005), ‘The origin of bursts and heavy tails in human dynamics’, Nature, 435(7039), 207-211  Battiston, S, Farmer, J D, Flache, A, Garlaschelli, D, Haldane, A G, Heesterbeek, H, and Scheffer, M (2016), ‘Complexity theory and financial regulation’, Science, 351(6275), 818-819 Batty, M, Desyllas, J and Duxbury, E (2003), ‘Safety in Numbers?

At the macro level, they have been used to simulate and reproduce the way stars produce energy, using a nuclear fusion reactor here on Earth, an approach that has the potential to provide clean energy for billions of years (Turrell (2013)). Simulating the processes powering stars is modest by comparison with ABMs which aim to model the entire universe. In 1985, one of the first comprehensive computational models of the universe was published, with over 32,000 particles representing known matter (Davis et al (1985)). As estimates put the number of 80  protons and neutrons in the Universe at 10 , this ABM was impressively parsimonious (Penrose (1999)). These models have generated important insights, including the role of “dark matter” in the evolution of galaxies. Not all applications of ABMs are, however, large in scale and universal in application. A 1987 paper called “Why the Brazil Nuts Are on Top” used an ABM with agents of different physical sizes to explain how mixed nuts segregate over time when shaken, with Brazil nuts generally rising to the surface (Rosato et al (1987)). This research was not as nuts as it sounds. It has since found real-world applications in industries such as pharmaceuticals and manufacturing. 14  All speeches are available online at www.bankofengland.co.uk/publications/Pages/speeches/default.aspx  14  Figure 6: Segregation of nuts  Figure 7: The universe  Source: Sae Rpss (CC-BY-SA-3.0). Nuts (image available here). Source: NASA Headquarters - Greatest Images of NASA (NASA-HQ-GRIN) (public domain). Spiral galaxy in the constellation Coma Berenices (image available here).