The size of the Target 2 accounts held by national central banks in the euro zone
Germany and the Netherlands hold substantial Target 2 assets (respectively EUR 650bn and EUR 140bn), while Greece, Spain, Italy and Ireland have substantial Target 2 debts (respectively EUR 98bn, EUR 285bn, EUR 280bn and EUR 117bn).
Fundamentally, these are currency interventions
Let us take, for example, the Germany/Spain pair. If the Bundesbank lends to the Bank of Spain, there is an increase in Germany's positive Target 2 account and in Spain’s negative Target 2 account. This corresponds to a loan from Germany to Spain, or to a purchase of Spanish assets by the German central bank.
If this purchase had not taken place, Spain would be unable to finance its external deficit, and would be forced to pull out of the euro and let its currency depreciate to the point where capital inflows covered its external borrowing requirement.
Therefore, this is the exact equivalent of a currency intervention aimed at ensuring the stability of the exchange rate between Germany and Spain: the country with a "strong currency" buys assets of the country with a "weak currency" to stabilise the exchange rate.
Similarity with the China/United States pair
When China accumulates foreign exchange reserves in dollars to prevent an excessive appreciation of the RMB against the dollar, the People's Bank of China holds US assets and the United States, conversely, has a debt to China.
This operation increases the size of the balance sheet of the People's Bank of China, and therefore leads to monetary creation.
Likewise, when the Bundesbank lends to central banks in the Southern euro-zone countries, and these central banks subsequently lend these funds to the banks in their own countries, there is a creation of monetary base in euros.
Target 2 accounts measure the risk of a break-up of the euro
The size (positive or negative according to the country) of the Target 2 accounts held by the central banks in the euro zone therefore represents the size of the foreign exchange reserves that the euro zone countries with a "strong currency" have to accumulate to ensure the euro’s sustainability ("exchange-rate stability" between euro zone countries). The more the size of these accounts increases, the higher the risk that the euro may break-up.
Positive Target 2 accounts surged from the summer of 2011, and this went hand in hand with a period of pressure on the interest rates on peripheral government bonds and on risk premia on banks.