Sidu River Bridge in Hubei Province, China, the world's highest bridge.  (Wikimedia Commons.)

China's Asian Infrastructure Investment Bank (AIIB) initiative was has spurred an explosion of opinion and analysis. The Asian Development Bank's (ADB) 2009 estimate that Asia will need US$8.22 trillion in infrastructure investment is the headline figure used to explain the importance of the new bank. Much of the opinion expressed so far has also assumed that the AIIB will be, as the main Chinese media agency Xinhua puts it, a Chinese gift to the world, with China as the main creditor.

But looking more closely at the ADB's figures and at China's present interactions with the World Bank and ADB, a more interesting possibility emerges that has so far escaped attention or analysis.

China, befitting its huge size and developing-economy status, could be a major AIIB borrower. China's own infrastructure needs alone account for over half of the total for Asia, according to the 2009 ADB estimate. In 2014, China was second-largest recipient of ADB loans after India. This was also the case in 2013. Likewise, China has the second-largest present borrowing obligations with the World Bank (at US$17.2 billion) after India (at US$36.4 billion).

Will the lending portfolio of the AIIB follow suit? Asia's present infrastructure needs and China's use of the existing development banks suggest it should.