Regulatory Capital

Capital requirement (also known as regulatory capital or capital adequacy) is the amount of capital a bank or other financial institution has to hold as required by its financial regulator. This is usually expressed as a capital adequacy ratio of equity that must be held as a percentage of risk-weighted assets. These requirements are put into place to ensure that these institutions do not take on excess leverage and become insolvent. Capital requirements govern the ratio of equity to debt, recorded on the liabilities and equity side of a firm's balance sheet. They should not be confused with reserve requirements, which govern the assets side of a bank's balance sheet—in particular, the proportion of its assets it must hold in cash or highly-liquid assets.

A key part of bank regulation is to make sure that firms operating in the industry are prudently managed. The aim is to protect the firms themselves, their customers, the government (which is liable for the cost of deposit insurance in the event of a bank failure) and the economy, by establishing rules to make sure that these institutions hold enough capital to ensure continuation of a safe and efficient market and able to withstand any foreseeable problems.

The main international effort to establish rules around capital requirements has been the Basel Accords, published by the Basel Committee on Banking Supervision housed at the Bank for International Settlements. This sets a framework on how banks and depository institutions must calculate their capital. After obtaining the capital ratios, the bank capital adequacy can be assessed and regulated. In 1988, the Committee decided to introduce a capital measurement system commonly referred to as Basel I. In June 2004 this framework was replaced by a significantly more complex capital adequacy framework commonly known as Basel II. Following the financial crisis of 2007–08, Basel II was replaced by Basel III, which will be gradually phased in between 2013 and 2019.

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