Mervyn King said recently it could be six to nine months until we know whether quantitative easing has worked. You can see why. The lending figures from the first two months of the policy aren't exactly a shot in the arm.
Credit conditions have eased since the start of the year, and the Bank of England can take some credit for that - though more thanks to its interest rate cuts than its move to inject billions of pounds of money into the economy via QE. We saw another modest rise in mortgage approvals today.
The Bank's purchases of corporate debt under QE also seem to have encouraged larger companies to put more debt on to the market. That was one of the Bank's stated goals when it kicked off the policy in early March.
But - and it's a fairly big but - a major focus of the policy has always been raising the broad money supply, or lending to companies and households across the economy, also known as M4. That was what distinguished QE from more traditional monetary policy.
By purchasing bonds (mainly government debt, or gilts) from non-bank institutions using fresh central bank money, the Bank of England was hoping to get more cash out into the economy directly, without entirely relying on the banks to lend it on. But growth in lending to households has barely changed in the past three months, growing at an annualised rate of around 2%. And by the same measure, lending to non-financial companies actually actually fell in April. Overall, the stock of M4 lending actually fell by £9bn in April, which I am told is by far the largest ever decline in a single month.
Now, there are plenty of explanations for all this. For one - we are in the depths of a recession. Even without a credit crunch, recessions don't tend to be associated with buoyant lending. The sharp decline in M4 lending (much of it traditional bank lending) might also be partly due to QE itself - if companies are using improved conditions in the markets to issue commercial paper and pay off expensive bank loans.
Bank officials would say there's been too much going on in the markets and the economy the past few months to be able to isolate the effects of QE - even £75bn-worth of it. The same applies to the rise in long-term interest rates during the past few months, primarily the interest rate - or yield - on government debt.
Other things equal, you would have expected that risk-free borrowing rate to fall as a result of QE, thus easing market conditions across the board. But, as I've discussed before, other things have not been equal. For one thing, there's been the small matter of the Budget and some pretty eye-watering deficit forecasts. Mervyn King seems to think things would have been worse for the bond market without QE, and probably for bank lending as well.
Still, it says something about the subdued state of our economy - and especially our financial system - that a cash injection worth more than 5% of GDP in just three months can sink, almost without trace.
For the true QE believers, such as Jamie Dannhauser at Lombard Street Research, the still weak state of corporate lending makes it even more important for the Bank to press ahead. If it wants to see broad money growing at 6-8% a year, he thinks it's a forgone conclusion that the Bank will use up its £150bn initial allotment for the policy, and it could spend much more than that by the end of the year.
That's quite a leap from just two months of data. But I don't think the members of the MPC when they start their meeting tomorrow will see reason to spend any less.