A well known economic identity states:
Snational = Inational + CAB
where Snational and Inational are national saving and national investment and CAB is the current account balance of international payments. In calculating national saving and investment, one adds saving and investment, respectively, of all resident sectors of the economy.
However, an accounting identity shouldn’t be confused with behavioural relationships.
Steven Roach is a good economist and it’s sad to see him confusing this. In a recent article for Project Syndicate titled America’s Trade Deficit Begins at Home, he uses this identity to conclude that if America wants to reduce her trade deficit, the solution is more saving.
Roach says:
What the candidates won’t tell the American people is that the trade deficit and the pressures it places on hard-pressed middle-class workers stem from problems made at home. In fact, the real reason the US has such a massive multilateral trade deficit is that Americans don’t save.
Total US saving – the sum total of the saving of families, businesses, and the government sector – amounted to just 2.6% of national income in the fourth quarter of 2015. That is a 0.6-percentage-point drop from a year earlier and less than half the 6.3% average that prevailed during the final three decades of the twentieth century.
Any basic economics course stresses the ironclad accounting identity that saving must equal investment at each and every point in time. Without saving, investing in the future is all but impossible.
A little thought on behavioural relationships tell a different story. The main causality connecting accounting identities is behaviour of demand and output at home and abroad. While it is true that by accounting identity, the U.S. current account balance will improve by more saving (such as households saving more, firms retaining higher earnings and government (both at the federal and state level) attempting to increase its saving tighten fiscal policy, it happens via a contraction of output.
Wynne Godley was one who stressed this before the crisis. In his paper The United States And Her Creditors: Can The Symbiosis Last? written with Dimitri Papadimitrou, Claudio Dos Santos and Gennaro Zezza, this is made clear:
A well-known accounting identity says that the current account balance is equal, by definition, to the gap between national saving and investment. (The current account balance is exports minus imports, plus net flows of certain types of cross-border income.) All too often, the conclusion is drawn that a current account deficit can be cured by raising national saving—and therefore that the government should cut its budget deficit. This conclusion is illegitimate, because any improvement in the current account balance would only come about if the fiscal restriction caused a recession. But in any case, the balance between saving and investment in the economy as a whole is not a satisfactory operational concept because it aggregates two sectors (government and private) that are separately motivated and behave in entirely different ways. We prefer to use the accounting identity (tautology) that divides the economy into three sectors rather than two—the current account balance, the general government’s budget deficit, and the private sector’s surplus of disposable income over expenditure (net saving)—as a tool to bring coherence to the discussion of strategic issues. It is hardly necessary to add that little or nothing can be learned from these financial balances measured ex post until we know a great deal more about what else has happened in the economy—in particular, how the level of output has changed
[boldening: mine]
This was pre-crisis from a few who were avowed Keynesians all their life! It’s unfortunate to see Steve Roach make an error even after so many years into the global economic and financial crisis. One should study Keynes seriously. While I am sure Roach appreciates the paradox of thrift, he forgets applying it to the analysis of United States of America’s trade deficits.