Yesterday’s Bank of England news release states that “the Committee will monitor the effectiveness of this purchase programme in boosting the supply of money and credit”. However, the MPC needs to clarify which monetary measures it is monitoring and how big a boost it is aiming to achieve.

Headline M4 and M4 lending numbers are unusable at present, having been inflated by an explosion in money holdings and bank borrowing of “intermediate other financial corporations”. This reflects the replacement of traditional unsecured interbank borrowing and lending by secured forms of lending channelled through off-balance-sheet entities and third parties such as the London Clearing House.

The MPC will probably focus on the Bank of England’s adjusted M4 and lending measures, which exclude these financial intermediaries. Annual growth rates are published quarterly in a chart in the Inflation Report, with underlying data provided in a spreadsheet. Adjusted M4 rose by an annual 3.8% in December versus 16.1% for headline M4; the corresponding numbers for adjusted and headline M4 lending were 3.8% and 15.9%. Bank statisticians also calculate monthly estimates for the MPC meetings but these are not currently published (I have submitted a request for access under freedom of information provisions).

While it is not possible to derive the Bank of England’s adjusted measures from published data, monthly figures can be calculated for M4 and lending excluding all financial corporations, i.e. covering only households and non-financial companies. The latest annual growth rates, for January, were 2.8% and 4.9% respectively. Asset purchases, however, will boost the money holdings of traditional financial institutions – insurance companies, pension funds, unit and investment trusts etc. – in the first instance so the omission of the financial sector is a major disadvantage for monitoring the progress of the scheme.

A previous post argued that the MPC should aim to deliver a five percentage point boost to the annual growth rate of adjusted M4, i.e. from 3.8% to about 9%. The announced programme looks consistent with this target but the MPC should be prepared to adjust operations – in either direction – in light of incoming monetary data.

The key elements of the announcements today were:

1. The existing asset purchase facility of up to £50 billion has been expanded to up to £150 billion, with gilt-edged securities added to the list of eligible assets, and purchases to be financed by the creation of central bank money rather than Treasury bill issuance.

2. The MPC has initially authorised purchases of £75 billion over three months. Gilts are likely to account for the majority of this amount. Purchases will be of medium- and long-maturity conventional (i.e. not index-linked) gilts.

3. The effectiveness of the programme will be judged by its impact on the supply of money and credit but the MPC has failed to specify any quantitative targets. The relevant monetary aggregate is presumably the broad money supply, M4, but this is not confirmed.

4. The MPC cut Bank rate by a further 0.5 percentage points despite possible “counter-productive effects on the operation of some financial markets and on the lending capacity of the banking system”. This suggests a split decision. The further cut is logically inconsistent with the reduction of only 0.5 percentage points last month – the MPC agreed that additional stimulus was required but judged that cutting below 1% might have no positive impact on the economy.

The welcome aspects of the announcements are that asset purchase plans are on the right scale – £150 billion is equivalent to 7.5% of M4 – and the focus on buying medium- and long-term gilts will maximise the monetary impact. (This is because longer-term gilts are held mostly outside the banking system so purchases will boost non-bank domestic investors’ bank deposits, included in M4.)

Less impressive is the MPC’s failure to specify a target impact on M4 and lending, or to make a commitment to reining back monetary growth once economic recovery is established to ensure there are no longer-term inflationary consequences. In addition, the Bank rate cut was not necessary to implement quantitative easing and is likely to put further pressure on banks’ interest margins, with negative implications for credit supply.

In the same way that individuals and companies settle transactions using accounts at commercial banks, banks themselves have accounts at the central bank that they use for clearing purposes. Quantitative easing – or tightening – refers to central bank actions that expand or contract the supply of funds held in these reserve accounts.

In operating monetary policy, central banks can alter either the price of money – interest rates – or the quantity of reserves. In recent years interest rate changes have been the dominant tool but historically policy-makers also used quantitative actions to achieve their goals.

A cut in interest rates boosts the economy by stimulating spending and borrowing. Higher bank borrowing results in an expansion in the amount of money in individuals’ and firms’ bank accounts – the broad money supply. This monetary expansion leads to further increases in spending and economic activity.

With quantitative easing, the central bank buys securities from the private sector and pays for them by crediting banks’ reserve accounts – effectively creating new reserves by the click of a mouse. This can boost the economy in two ways. First, if the central bank buys from individuals or firms, the money in their accounts with commercial banks increases, matching the rise in the banks’ reserves with the central bank. This increase in the broad money supply then encourages higher spending.

Secondly, the higher level of reserves may encourage commercial banks to lend more. The higher lending may be associated with a rise in spending and results in a further expansion of the broad money supply, with additional stimulative effects.

Quantitative easing is appropriate currently because interest rates are already exceptionally low and cuts may fail to stimulate borrowing and spending because individuals and firms wish to reduce their debt. A clear sign that interest rates are providing insufficient stimulus is the low rate of growth of the broad money supply.

Quantitative easing is capable of directly boosting money supply growth to the level required to generate an economic recovery. To ensure the necessary impact, however, it is important that the central bank purchases securities from companies and families rather than banks. Buying from banks boosts the broad money supply only if the higher level of reserves causes them to expand their lending. In current circumstances, with banks constrained by lack of capital and potential borrowers reluctant to increase their debt, any such effect might be small.

The annual growth rate of the broad money supply, M4, adjusted for distortions caused by the financial crisis, is currently about 4%. A rise towards 10% is probably necessary to generate an economic recovery. To achieve a boost on this scale, the Bank of England may need to buy £125 billion or more of securities. In order to implement the scheme quickly while minimising distortions to market prices, the Bank should concentrate purchases in gilts rather than corporate bonds or other private sector paper. Statistical work suggests that a programme on this scale could boost gross domestic product (GDP) by more than 1% after a year.

Could quantitative easing lead to an upsurge in inflation? Not so long as policy-makers ensure that the monetary boost is temporary. Once recovery is established, broad money supply growth will need to be reined back to about 6-7% per annum to ensure consistency with the 2% inflation target over the medium term.

Amid current deep gloom, are there any signs that global economic clouds could lift later in 2009?

The most hopeful message continues to come from monetary trends. Annual growth in G7 real narrow and broad money has been picking up since August / September last year, rising further in January – see first chart. Money growth typically leads industrial output momentum by 6-12 months, suggesting a bottom in the latter by late summer at the latest.

One reservation is that the monetary acceleration has been heavily dependent on the US, reflecting Fed asset purchases. Similar action is needed in other G7 economies, though the Bank of England should step up to the plate this week. In addition, the Fed must sustain the pace of asset purchases to prevent a relapse in money growth – buying has slowed in recent weeks.

Another glimmer of hope is that output has been falling much faster than final demand, allowing inventories to decline. While G7 industrial output plunged by an estimated 14% in the year to January, retail sales volumes were “only” 5.5% lower – second and third charts. GDP reports show significant declines in inventories in the US, France and the UK in the fourth quarter (Japan was a notable exception). This supports expectations that the stocks cycle will act to support economic activity later in 2009 – a positive impact requires only a slowdown in the pace of destocking, not an actual rise in inventories.

Shorter-term indicators remain mostly grim and labour market news should be especially awful over the next few months. Nevertheless, this week’s purchasing managers surveys at least suggest some slowdown in the pace of industrial contraction – fourth chart.

The spread between UK banks' average lending and deposit rates – a measure of their net interest margin – remained close to its historical low in January, according to estimates derived from Bank of England data published today. The spread stood at 2.08%, little changed from 2.09% in September before the MPC began slashing Bank rate and well below its average of 2.77% over 1999-2008 – see chart.

Some commentators accuse banks of widening margins by increasing the spread between lending rates and Bank rate, particularly for new and refinancing borrowers. The effect, however, has been offset by a rise in deposit rates relative to Bank rate. For example, the spread between Bank rate and the average rate paid on interest-bearing sight (i.e. instant access) deposits from households fell to just 0.47% in January versus an average of 2.20% over 1999-2008. In effect, banks have been forced to charge borrowers more in order to keep deposit rates high enough to retain funds.

The sight deposit rate stood at just 1.14% in January, a level that does not fully reflect the 0.5 percentage point reduction in Bank rate to 1.5% at the start of the month. The MPC cut by a further 0.5 pp in February and the consensus expects another 0.5 pp this week. If this is delivered, banks will face a choice between lowering sight deposit rates almost to zero, thereby risking a significant outflow of funds in favour of government-sponsored savings (National Savings / Northern Rock), or allowing a further narrowing of the Bank / deposit rate spread, with negative implications for profitability. Either way, their ability / willingness to lend may be impaired.

The MPC discussed possible adverse effects of a larger Bank rate cut at the February meeting. “There was a great deal of uncertainty about what would happen to banks’ and building societies’ willingness to lend at low levels of interest rates. It was possible that the negative impact on profitability could be significant for some banks as Bank rate fell further. Taking that into account, a majority of members concluded that a cut of 50 basis points was appropriate this month.”

If a sub-1% Bank rate was judged inappropriate last month, despite the MPC’s forecast of a significant inflation undershoot over the medium term, it would seem difficult to justify a further cut this week. Contrary to popular assertion, there is no technical requirement to reduce Bank rate towards zero before embarking on asset purchases designed to boost the money supply – see previous post for more discussion.