Imports are National Saving used for Investment

In the circular flow model that I use, as imports rise so does gross saving. And does that increased saving show up in increased investment? How would imports lead to more investment?

Here is the model as a closed economy without imports and exports using 1st quarter-2011 data as an example.

Circular flow ext 12

link to Graph #1

This graph simply takes out imports and exports from the data. Now start at gross saving, $3,059 billion. Part of that money is then lent to the government, $1,391 billion. The remainder is used for investment, $1,668 billion. So we have the equality…

S – I = G – T

3059 – 1668 = 3012 – 1621

G = govt. spending… T = net taxes… S = gross saving… I = investment

There is another way to get the same equation in the model. The row for leakages is equal to the row for injections. Here is the equation and then simplified. (C = consumption)

C + T + S = C + G + I

C + T + S (leakages)… C + G + I (injections)

Cancel out C from both sides and rearrange…

T + S = G + I

(S – I) = (G – T)

Now we will open up this model to foreign markets. Here is the data from 1st quarter 2011 including imports and exports.

Circular flow ext 11

link to Graph #2

I want you to see that gross saving increased from $3,059 billion to $5,370 billion. The increase was $2,311 billion… the same amount as imports.

So how do imports directly raise gross saving?

When we buy an import, where does our money go? It goes into the foreign exchange market. The foreign exporter then receives their own currency from the foreign exchange market. And our dollars remain in the foreign exchange market.

But now what happens with the dollars sitting in the foreign exchange market? Theoretically they must come back to the United States to either purchase US assets, goods and services (exports) or to be invested in the United States. Theoretically, those dollars sitting in the foreign exchange markets are part of the gross saving of the United States. Thus, gross saving in graph #2 includes money in the foreign exchange market.

So what do we see happen in graph #2? Of the $2,311 billion that went into the foreign exchange market from imports, $1,855 billion came back from the foreign exchange market when foreigners bought US goods and services. We see that $1,855 billion leaving the financial sector “Lend (-)/borrow” entry going to the export entry.

So what happened with the $456 billion difference between imports and exports that was still left in the foreign exchange market? That $456 billion moved right down into the investment entry of $2,124 billion. That $456 billion was eventually invested in the United States. Notice that investment rose $456 billion from graph #1 to graph #2 (from $1,668 billion to $2,124 billion).

So then what does the entry for net exports of -$456 billion mean? In effect, the entry of -$456 billion of net exports is an accounting entry to close the books at the end of the year representing the money that flowed back from the foreign exchange market for investment in the US. In actuality, that $456 billion stayed in US gross saving account, even though it was transferred back by transactions with foreigners. The accounting entry simply balanced the books with the foreign sector.

They don’t call it National Income Accounting for nothing.

Correcting the Twin Deficits Hypothesis

In the circular flow model above, look at the row where the leakages are. The row has the equation…

C + T + S – M

C = consumption… T = net taxes… S = gross saving… M = imports

Now look at the row for “injection returns/expenditures”. The row has the equation…

C + G + I + X – M

C = consumption… G = govt spending… I = investment… X – M = net exports

Now the two equations above are equal.

C + T + S – M = C + G + I + X – M

We cancel out C and M from both sides.

T + S = G + I + X


(S – I) + (T – G) = X

Some of you should be saying… “That can’t be right, the correct equation is…”

(S – I) + (T – G) = (X – M)

This is the equation usually seen from the Twin Deficits Hypothesis. The implication of this equation is that as the govt budget deficit increases, G>T, holding saving constant, that either investment must fall, or the trade deficit must increase. Basically, government deficits worsen the economy.

However, once you realize that imports create an equal amount of savings for investment, you realize that the correct equation is…

(S – I) + (T – G) = X

Imports are inside gross saving, S, by way of the foreign exchange market. From the above graph, the equation comes out like this…

(5370 – 2124) + (1621 – 3012) = 1855

1855 = 1855

The equation is like this… If you increase the government deficit by raising G in the equation, holding exports constant since it is determined by foreign demand, investment would fall. However, a country does have the option to raise gross saving by importing more. Imports are gross saving used for investment. Consequently, investment would not fall.

Currently, people want to support investment. Maybe by increasing imports, we can support investment. But really, raising labor income is still the best way to raise domestic investment. More labor income would increase consumption and it would increase saving through more personal savings and more purchases of imports.