  We briefly review the well-known risks, weaknesses and limitations of
spreadsheets and then introduce some more. We review and slightly extend our
previous work on the importance and criticality of spreadsheets in the City of
London, introducing the notions of ubiquity, centrality, legality and
contagion. We identify the sector of the financial market that we believed in
2005 to be highly dependant on the use of spreadsheets and relate this to its
recent catastrophic financial performance. We outline the role of spreadsheets
in the collapse of the Jamaican banking system in the late 1990's and then
review the UK financial regulator's knowledge of the risks of spreadsheets in
the contemporary financial system. We summarise the available evidence and
suggest that there is a link between the use of spreadsheets and the recent
collapse of the global financial system. We provide governments and regulating
authorities with some simple recommendations to reduce the risks of continued
overdependence on unreliable spreadsheets. We conclude with three fundamental
lessons from a century of human error research.
