When you consider how many people worry about the federal government's debt, it's surprising how rarely we hear about the nation's much bigger foreign debt. When it reached $1 trillion more than a year ago, no one noticed.
That's equivalent to 60 per cent of the nation's annual income (gross domestic product), whereas the federal net public debt is headed for less than a third of that – about $320 billion – by June.
Similarly, when you consider how much people worry about the future of the Chinese economy, American interest rates and all the rest, it's surprising how little interest we take in our "balance of payments" – a quarterly summary of all our economic transactions with the rest of the world.
Note, I'm not saying we should be worried about our foreign debt. We already do more worrying about the federal government's debt than we need to.
No, I'm just saying it's funny. Why do we worry about some things and not others?
Short answer: the politicians don't want to talk our "external sector" because it sounds bad. The economists don't want to talk about it because they know it isn't bad.
But since we're on the subject – and since Reserve Bank deputy governor Dr Guy Debelle gave a speech about it this week – let's see what's been happening while our attention's been elsewhere.
If you're unsure of the difference between the two debts, it's simple. The federal net public debt is all the money owed by the federal government to people, less all the money people owe it (hence that little word "net").
According to Debelle, about 60 per cent of all bonds issued by the feds is owed to foreigners and 40 per cent to Australian banks and investors. About a quarter of all bonds issued by the state governments is held by foreigners.
In contrast, the nation's net foreign debt is all the money Australian businesses and governments (and any other Aussies) owe to foreigners, less what they owe us. (For every $1 we owe them, they owe us 52¢.)
But how did we rack up so much debt?
Long story. Let's start with the balance of payments, which is divided into two accounts. The "current" account shows the money we earn from all our exports of goods and services, less the money we pay for all our imports, giving our "balance on trade".
Our imports usually exceed our exports, giving us a trade deficit. This deficit has to be funded (paid for) either by borrowing from foreigners or by having them make "equity" (ownership) investments in Australian businesses or properties.
Of course, when we borrow from foreigners, we have to pay interest on our debts. And when foreigners own Australian businesses, they're entitled to receive dividends.
The interest and dividends we pay to foreigners, less the interest and dividends they pay us (actually, our superannuation funds and Australian multinationals), is the "net income deficit".
We've been running trade deficits for so long, and racking up so much net debt to foreigners, that the net income deficit each quarter is much bigger than our trade deficit.
But add the trade deficit and the net income deficit (plus some odds and ends) and you get the deficit on the current account of the balance of payments.
The money that comes in from various foreign lenders and investors to cover the current account deficit is shown in its opposite number, the "capital and financial account".
Because the price of our dollar (our exchange rate) is allowed to float up and down until the number of Aussie dollars being bought and sold is equal, the deficit on the current account is at all times exactly matched by a surplus on the capital account, representing our "net [financial] capital inflow" for the quarter.
It turns out that, in the years since the global financial crisis of 2008-09, the current account deficit has narrowed.
In the 14 years to then, it averaged 4.8 per cent of GDP. In the years since then it's averaged 3.5 per cent. And in calendar 2016 it was just 2.6 per cent.
Why has it narrowed? Well, Debelle explains it's mainly a reduction in the net income deficit component of the overall deficit, which is at its lowest as a percentage of GDP since the dollar was floated in 1983.
The rates of interest we're paying on our foreign debt are lower because Australian – and world – interest rates are a lot lower since the crisis. And our dividend payments to foreign owners of Australian companies fell as the fall in coal and iron ore prices hit mining company profits.
That's nice. But while ever we have any deficit on the current account, our foreign debt will grow, and it already exceeds $1 trillion. Isn't that a worry?
Not really. It's not growing faster than our economy (GDP) is growing, and thus our ability to afford the interest payments.
More to the point, the current account deficit is just the counterpart to all the foreign capital flowing into Australia and helping us develop our economy faster than we could without foreign help.
The proof that such a massive debt doesn't mean we're "living beyond our means" is, first, that the nation – households, businesses and governments combined – saves a high proportion of its income rather than spending it on consumption.
Everything the nation saves each year is used to fund new investment in houses, business structures and equipment, and infrastructure. This investment is further proof we're not living beyond our means.
In fact, the nation invests more each year than we save. Huh? Well, the extra funding is borrowed from foreigners.
You can call it the surplus on the capital account of the balance of payments, or the "net foreign capital inflow" or – get this – the current account deficit.
