Amplification Mechanisms
One of the mechanisms, that can work to amplify the effects of a small negative shock to the economy, is the Balance Sheet Mechanism. Under this mechanism, a negative shock in the financial market lowers asset prices and erodes the financial institution’s capital thus worsening its balance sheet. Consequently, two liquidity spirals come into effect, which amplify the impact of the initial negative shock. In an attempt to maintain its leverage ratio, the financial institution must sell its assets, precisely at a time when their price is low. Thus, assuming that asset prices depend on the health of investors’ balance sheet, erosion of investors’ net worth further reduces asset prices, which feeds back into their balance sheet and so on. This is what Brunnermeier and Pedersen (2008) term as the "loss spiral". At the same time, lending standards and margins tighten, leading to the "margin spiral". Both these effects cause the borrowers to engage in a fire sale, lowering prices and deteriorating external financing conditions.
Apart from the "Balance Sheet Mechanism" described above, the lending channel can also dry up for reasons exogenous to the borrower’s credit worthiness. For instance, banks may become concerned about their future access to capital markets in the event of a negative shock and may engage in precautionary hoarding of funds. This would result in reduction of funds available in the economy and a slowdown in economic activity. Additionally, the fact that most financial institutions are simultaneously engaged in lending and borrowing can give rise to a Network effect. In a setting that involves multiple parties, a gridlock can occur when concerns about counterparty credit risk result in failure to cancel out offsetting positions. Each party then has to hold additional funds to protect itself against the risks that are not netted out, reducing liquidity in the market. These mechanisms may explain the ‘gridlock’ observed in the interbank lending market during the recent subprime crisis, when banks were unwilling to lend to each other and instead hoarded their reserves.
Besides, a liquidity crisis may even result due to uncertainty associated with market activities. Typically, market participants jump on the financial innovation bandwagon, often before they can fully apprehend the risks associated with new financial assets. Unexpected behaviour of such new financial assets can lead to market participants disengaging from risks they don’t understand and investing in more liquid or familiar assets. This can be described as the Information Amplification Mechanism. In the subprime mortagage crisis, rapid endorsement and later abandonment of complicated structured finance products such as Collateralized debt obligations, Mortgage-backed securities etc. played a pivotal role in amplifying the effects of a drop in property prices.
Read more about this topic: Liquidity Crisis