Payment and Debt Ratios

In most countries, a number of more or less standard measures of creditworthiness may be used. Common measures include payment to income (mortgage payments as a percentage of gross or net income); debt to income (all debt payments, including mortgage payments, as a percentage of income); and various net worth measures. In many countries, credit scores are used in lieu of or to supplement these measures. There will also be requirements for documentation of the creditworthiness, such as income tax returns, pay stubs, etc; the specifics will vary from location to location.

Some lenders may also require a potential borrower have one or more months of "reserve assets" available. In other words, the borrower may be required to show the availability of enough assets to pay for the housing costs (including mortgage, taxes, etc.) for a period of time in the event of the job loss or other loss of income.

Many countries have lower requirements for certain borrowers, or "no-doc" / "low-doc" lending standards that may be acceptable in certain circumstances.

Loan to Value And Downpayments

Upon making a mortgage loan for the purchase of a property, lenders usually require that the borrower make a downpayment; that is, contribute a portion of the cost of the property. This downpayment may be expressed as a portion of the value of the property (see below for a definition of this term). The loan to value ratio (or LTV) is the size of the loan against the value of the property. Therefore, a mortgage loan in which the purchaser has made a downpayment of 20% has a loan to value ratio of 80%. For loans made against properties that the borrower already owns, the loan to value ratio will be imputed against the estimated value of the property.

The loan to value ratio is considered an important indicator of the riskiness of a mortgage loan: the higher the LTV, the higher the risk that the value of the property (in case of foreclosure) will be insufficient to cover the remaining principal of the loan.

Counterparty risk

Counterparty risk, otherwise known as default risk, is the risk that an organization does not pay out on a bond, credit derivative, credit insurance contract, or other trade or transaction when it is supposed to.Even organizations who think that they have hedged their bets by buying credit insurance of some sort still face the risk that the insurer will be unable to pay, either due to temporary liquidity issues or longer term systemic issues.

Large insurers are counterparties to many transactions, and thus this is the kind of risk that prompts financial regulators to act, e.g., the bailout of insurer AIG.

On the methodological side, counterparty risk can be affected by wrong way risk, namely the risk that different risk factors be correlated in the most harmful direction. Including correlation between the portfolio risk factors and the counterparty default into the methodology is not trivial

Sovereign risk

Sovereign risk is the risk of a government becoming unwilling or unable to meet its loan obligations, or reneging on loans it guarantees.The existence of sovereign risk means that creditors should take a two-stage decision process when deciding to lend to a firm based in a foreign country. Firstly one should consider the sovereign risk quality of the country and then consider the firm's credit quality.

Five macroeconomic variables that affect the probability of sovereign debt rescheduling are:

• Debt service ratio
• Import ratio
• Investment ratio
• Variance of export revenue
• Domestic money supply growth

The probability of rescheduling is an increasing function of debt service ratio, import ratio, variance of export revenue and domestic money supply growth. Frenkel, Karmann and Scholtens also argue that the likelihood of rescheduling is a decreasing function of investment ratio due to future economic productivity gains. Saunders argues that rescheduling can become more likely if the investment ratio rises as the foreign country could become less dependent on its external creditors and so be less concerned about receiving credit from these countries/investors.

Assessing credit risk

Significant resources and sophisticated programs are used to analyze and manage risk. Some companies run a credit risk department whose job is to assess the financial health of their customers, and extend credit (or not) accordingly. They may use in house programs to advise on avoiding, reducing and transferring risk. They also use third party provided intelligence. Companies like Standard & Poor's, Moody's Analytics, Fitch Ratings, and Dun and Bradstreet provide such information for a fee.

Most lenders employ their own models (credit scorecards) to rank potential and existing customers according to risk, and then apply appropriate strategies. With products such as unsecured personal loans or mortgages, lenders charge a higher price for higher risk customers and vice versa. With revolving products such as credit cards and overdrafts, risk is controlled through the setting of credit limits. Some products also require security, most commonly in the form of property.

Credit scoring models also form part of the framework used by banks or lending institutions grant credit to clients. For corporate and commercial borrowers, these models generally have qualitative and quantitative sections outlining various aspects of the risk including, but not limited to, operating experience, management expertise, asset quality, and leverage and liquidity ratios, respectively. Once this information has been fully reviewed by credit officers and credit committees, the lender provides the funds subject to the terms and conditions presented within the contract (as outlined above).

Credit risk has been shown to be particularly large and particularly damaging for very large investment projects, so-called megaprojects. This is because such projects are especially prone to end up in what has been called the "debt trap," i.e., a situation where – due to cost overruns, schedule delays, etc. – the costs of servicing debt becomes larger than the revenues available to pay interest on and bring down the debt.