Although productivity growth 1/7  BIS central bankers' speeches  had been slowing since the mid-1990s, agents overestimated future income growth and borrowed against it, accumulating excessive levels of debt. At the same time, poor risk management, low capital and liquidity, inadequate corporate governance, and weak supervision and regulation encouraged financial leverage, which led to the build-up of vulnerabilities.
This was particularly acute in the United States, where there was a rapid expansion in the development of complex financial securities, which later proved to entail substantial risks.