Does deficit spending increase national debt?

3 min read

A national economy, with a sovereign currency, is big money system. Unlike a household the independent inputs and outputs are not income and expenditure. The input to a national economy is currency that is introduced into the system through public spending. The output is the money that leaves to go abroad, as a trade deficit, currency that is saved by the private sector (households and business) and money that is removed from the system through taxation.

The diagram below illustrates this system for the UK in 2016. The government spent £745 billion1All data is approximate and values are indicative. Data was drawn from into the economy on things like health, education, welfare and pensions and defence etc. It removed £680 billion in tax (income tax, corporation tax, VAT etc).

We are net importer, so our trade deficit was approximately £87 billion. In other words this currency left the domestic economy.

To balance this, private sector savings had to reduce to by $22 billion to meet the shortfall. For many individuals this means increased private debt. In other words £22 billion was introduced into the economy from the private sector. The private sector was using reserves or borrowing to deal with a private sector deficit created by government economic policy.

This model is the idea of former University of Cambridge economics professor and government adviser, Wynne Godley. Godley proposed that all surpluses had to match all deficits in the economy. This an accounting fact and not an economic theory.

A government with a sovereign currency does not borrow to spend . It simply credits the accounts of health trusts, local governments and welfare recipients.

Then, it is important to understand how the national debt arises.

Government bonds or gilts are used to reduce excess reserves accumulated in private sector saving accounts in commercial banks. This is necessary to maintain interest rates. If savings are too large then interest rates, as a result of supply and demand, will have to reduce. In order to stop them going negative the government has to reduce the amount of saving by exchanging currency reserves for bonds.

The private sector and its investors, in times of economic certainty prefer to limit risk. Government bonds are one of the least risky investments even though returns might be low. When the government cuts spending, like the Conservative-led government in the UK since 2010, demand reduces and private debt increases. Investing in business or development becomes risky, there is uncertainty that there will be sufficient demand to make the business sustainable. Currency that has gone overseas in trade or that has been accumulated in the domestic private sector ends up in banks and it is necessary for the government to exchange these for bonds, i.e. to increase the national debt.

This explains why, even when we cut spending, the national debt does not reduce and can even increase (see chart below). In fact, taking Wynne Godley’s approach demonstrates that the normal operating condition of a healthy economy is with a public sector deficit.

The period from 2010 shows a decrease in the deficit yet the national debt increased. It also happened 2004 to 2007 and 1993 to 1996. National debt is as much dependent on economic confidence as it is on public sector deficit.


Mitchell, W. F. (2016). Modern Monetary Theory and Practice: An Introductory text. CreateSpace Independent Publishing Platform.


  1. An excellent post, Steven. The only thing I would amend is “Tax Revenue” in your diagram. Tax is not a revenue. I would want to use “Tax appropriation, but it’s clumsy. What about just “Tax receipts”.

    Of course the so-called national debt is not a debt at all, it is a savings scheme, which I am sure you understand.

    Nit-picking, “least riskiest” should be “least risky”.

    1. Agree with all of this. Thank you. Have amended my English. My aim is to explain to those who have not thought about it how debt and deficit works – so forgive some of the clumsiness. But I am grateful for you supporting the fact that my overall explanation is accurate.

          1. Hi Steve,
            Nice article – one question.
            How is the interest generated on Bank created money represented in this model?
            As I understand it Bank created money gets created via fractional-reserve bank loans then over time is nominally destroyed as the loans are paid back. However the money used to pay the interest in the loans presumably has to be created by government in the long run.
            Does this mean it is part of the “Private Sector Savings” in the first diagram.

  2. Ian,

    I might be able to answer your question if I could understand what you are asking. I’ll initially try anyway using some assumptions. I am also not sure how far ahead you are with your knowledge of the Modern Monetary System, so forgive me if I might sound patronising.

    Are you asking about Central Bank-created money or Commercial Bank? I am assuming the former.

    If so, the money is not created by fractional reserve loans (nor is it for the latter for that matter). It is created ex-nihilo (ie out of thin air, although I dislike that term). There is, really, a box missing from the diagram in the form of the Central Bank which is, in MMT, treated as a part of the consolidated government sector. So the Treasury instructs the CB to credit the reserve account of the High Street Bank (HSB to avoid confusion) at which the target of its spending holds a current account. This increases the reserves of the HSB so it is able to credit the target’s current account with whatever the amount is.

    Exactly the same thing happens with an interest payment. The holder of a governmet security is entitled to a “coupon” payment at a certain date, and the government instructs the CB to credit the reserve account of the HSB at which the security holder has a current account. Again, the money is created ex-nihilo.

    Alongside this, the government looks at how much it has spent over a period and how much it has received in taxation and other fees and, purely as a matter of established procedure, it issues further securities to cover the difference between income and expenditure, assuming there is a deficit. To be slightly more accurate, it does this in advance so that there is a permanent “buffer”. It doesn’t actually have to in a fiat monetary system, but it has always done so since the Gold Standard, and it isn’t a bad rule of thumb anyway in order to stabilise interest rates.

    So the payment of interest happens in exactly the same way as the payment for goods or sevices, and the fugure appears on the Whole of Government Account resport. For 2015, for example, it was £83.6bn nett after adding a provision for pension scheme liabilities and deducting invesment income. It is not, however, included in the figures used for calculating the government fiscal deficit. Don’t ask me what figures are and are not – it’s a black art which I am trying to get to the bottom of.

    Does that help? Again I apologise if I am trying to teach granddad etc.

    Steven, please feel free to contradict me, this is your blog after all.

    1. Hi Nigel,
      Many thanks for your informative reply.
      I am still in the initial stages of “grocking” MMT so your comments about Central Bank CBs are helpful.
      I was actually referring to commercial banks HSBs with my first question but from your answer it looks like the CBs are actually creating the money loaned by the HSBs – Is that correct or did I miss something?
      I am still unclear as to how the interest paid on HSB loans is accounted for in Steve’s first diagram.

      1. First of all you need to understand how loans are actually created by HSBs, and you may be surprised to hear that it is not done by fractional reserve. It would be impossible for me to describe how it works in a few short sentences, but the gist is that when a bank makes a loan it adds the borrower’s promise to pay to its balance sheet – that is it is an asset of the bank – and then it creates an equal liability to the bank – that is the ability of the borrower to withdraw the funds. So effectively you are borrowing from yourself – or your future earnings. The banking system merely facilitates this process. There is a very good paper from the Bank of England that describes it, Working Paper No 259, which you can find on the BoE’s website.

        The creation of the interest the borrower pays happens in much the same way, but you would need to understand how the entire monetary system works to understand that. Believe me I have been studying it for well over two years now and I still get lots of things wrong.

        As a start off, if you want to get to have a better view, I would strongly recommend you read “Modern Money Theory” by L. Randall Wray which is available from the British Library or it costs about twenty pounds from Amazon. You will then see that you can never look at one small aspect such as where interest comes from without considering the entire monetary system – one thing interreacts with another. That is known as a complex system in mathematics.

  3. Hi Steven

    I’m very new to this MMT thinking and am admittedly sceptical. My largest scepticism is directed at the 22m shortfall, made up by the increase in private borrowing. How is this achieved in practice, as it would seem to be one of the things that is hardest to influence, let alone with the required precision.
    Additionally, you didn’t mention investments from overseas. Are these considered an off-set to the overall trade deficit?

    1. Hi Chris
      The first thing is to clear up the idea of sectoral balances. This was developed by the Cambridge economist Wynne Godley. It is an accounting identity, within a nation within its own sovereign currency. The government is the only source of currency (this has to be distinguished from the creation of money by private banks through lending). Overall then, the only source of currency within the system is the national government. And, the only way in which currency can be removed is through collecting taxes. Of course people can accumulate and save cash within the system.

      Sectoral balances tell us that, because there is only one input (gov spending) and one output (tax), then all surpluses must equal all deficits. Imagine if there were you and I in the economy, and I was running a surplus (earning more than I spend) then you must be running a deficit. You would then have to borrow to live.

      National accounting, by convention, is split into the public sector (government spending and taxation), private sector (business and households) and the rest of the world (imports, exports, overseas investments etc). These must all sum to zero. As I say, the importance of this is that it is an accounting identity not a theory. It means that if we have a current account deficit (i.e. net imports and currency leaving the UK) and a public sector deficit, there is a private sector surplus. It is important that there is private sector surplus so the private sector can save, the private sector has no control over the economy so it has to hold reserves.

      Now, if you try and reduce the public-sector deficit and create a surplus, then by sectoral balances (with the same deficit situation with the rest of the world) the private sector goes into deficit. This means that savings reduce or people have to take out loans to deal with the private sector deficit. This article illustrates this really well; .

      In answer to your questions, reducing public sector deficit with a current account deficit necessitates the private sector reducing their savings and taking out loans. The government can use legislation to make it easier to take loans. There are always those with capital looking to make money through lending.

      In terms of investment from overseas this, as you say, reduces the current account deficit – accumulated currency overseas is returned to the UK.

  4. As usual a very nice summary of how government surpluses/deficits equal private sector deficits/surpluses. I would add that when the private sector have a surplus they will save the surplus, even if it is only in a current bank account. Now, a good deal of these savings (I don’t have any figures, I’m afraid) end up in government bonds, so the so-called National Debt is the accumulation of all deficits in the past. But I prefer to think of the National Debt as the National Saving . The government can always repay the bonds when they become due as they are the issuer of the currency and, again because of the way they operate these days, they just then issue a new series of bonds for the same amount as that which was redemend. UK government bond issues are always oversubscribed. I admit I have not yet completed my own research on this subject, so my understanding is not complete either.

    In respect of your last paragraph, your readers need to understand that all transactions within a sovereign border can only be done in the currency of that border. A country that exports more than it imports ends up with a balance in (in our case of sterling) deposited at the Central Bank which they can only repatriate by buying goods in that currency – or gold. So the Chinese etc use that money to buy UK securities or to invest in UK industries. It is interesting that the Chinese have lately been buying huge quantities of gold. Again, my understanding is not complete.

  5. Great goods from you, man. I’ve understand your stuff previous to and you’re just too great. I actually like what you’ve acquired here, really like what you are stating and the way in which you say it. You make it enjoyable and you still care for to keep it smart. I can’t wait to read much more from you. This is actually a terrific site.|

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.