It should be noted that the method for updating multipliers is similar but different to the surrogate subgradient method, which is more robust and stable for accelerating the convergence rate.
Adding in the companies supporting the yards, and the shops and services that support these workers, the total ran to 400,000, an employment multiplier of 4.
In it, Keynes gave a much more complete account of how the multiplier might work, and how it might enable a government to drag a slumping economy back to health.