We have provided and then reinforced our forward guidance and, when rates reached the effective lower bound in September last year, we moved to asset purchases as the main tool of monetary policy, starting with two programmes of purchasing private assets and then expanding them to include public sector bonds last January.
We buy public sector assets with remaining maturities of two to 30 years, and the weighted average maturity of our portfolio is eight years. This is an unprecedented lengthening of the horizon at which we influence interest rates. 4 Both these instruments have been effective in overcoming the lower bound constraint.