The off-balance-sheet model, also known as the American model, is that the original owner (such as a bank) "sells" assets to a special purpose vehicle (SPV), and SPV re-establishes an asset pool after purchasing assets, and issues securities with the support of the asset pool; The on-balance-sheet model, also known as the European model, means that the original owner does not need to sell assets to SPV, but stays on his balance sheet, and the promoters issue securities themselves; The quasi-off-balance-sheet model is also called the Australian model, that is, the original owner sets up a wholly-owned or holding subsidiary as SPV, and then "sells" the assets to SPV. A subsidiary can buy not only the assets of the parent company, but also other assets. After purchasing assets, subsidiaries set up asset pools to issue securities.