The Asymmetric Relation Between Initial Margin Requirements and Stock Market Volatility Across Bull and Bear Markets, Review of Financial Studies 15(5), 1525–1559. [4]  Moore, T. (1966). Stock Market Margin Requirements. Journal of Political Economy 74,158–167. Fortune, P. (2001). Margin Lending and Stock Market Volatility, New England Economic Review 4, 3–26. [5]  Adrian, T. and H.S. Shin (2010). Liquidity and Leverage.
For after all, even if global macro-economic imbalances and accommodative monetary policy provided an enabling environment for excessive leverage and risk taking, it was still the responsibility of regulators and supervisors to have taken appropriate macro prudential measures, preemptively and proactively, rather than reactively, to prevent such an apocalyptic event.