Debt consolidation entails taking out one loan to pay off many others. This is often done to secure a lower interest rate, secure a fixed interest rate or for the convenience of servicing only one loan.

Debt consolidation can simply be from a number of unsecured loans into another unsecured loan, but more often it involves a secured loan against an asset that serves as collateral, most commonly a house. In this case, a mortgage is secured against the house. The collateralization of the loan allows a lower interest rate than without it, because by collateralizing, the asset owner agrees to allow the forced sale (foreclosure) of the asset to pay back the loan. The risk to the lender is reduced so the interest rate offered is lower.

Sometimes, debt consolidation companies can discount the amount of the loan. When the debtor is in danger of bankruptcy, the debt consolidator will buy the loan at a discount. A prudent debtor can shop around for consolidators who will pass along some of the savings. Consolidation can affect the ability of the debtor to discharge debts in bankruptcy, so the decision to consolidate must be weighed carefully.

Debt consolidation is often advisable in theory when someone is paying credit card debt. Credit cards can carry a much larger interest rate than even an unsecured loan from a bank. Debtors with property such as a home or car may get a lower rate through a secured loan using their property as collateral. Then the total interest and the total cash flow paid towards the debt is lower allowing the debt to be paid off sooner, incurring less interest.

Because of the theoretical advantage that debt consolidation offers a consumer that has high interest debt balances, companies can take advantage of that benefit of refinancing to charge very high fees in the debt consolidation loan. Sometimes these fees are near the state maximum for mortgage fees. In addition, some unscrupulous companies will knowingly wait until a client has backed themselves into a corner and must refinance in order to consolidate and pay off bills that they are behind on the payments. If the client does not refinance they may lose their house, so they are willing to pay any allowable fee to complete the debt consolidation. In some cases the situation is that the client does not have enough time to shop for another lender with lower fees and may not even be fully aware of them. This practice is known as predatory lending. Certainly many, if not most, debt consolidation transactions do not involve predatory lending.

Consumer debt is consumer credit which is outstanding. In macroeconomic terms, it is debt which is used to fund consumption rather than investment.

Some consider all debt incurred for anything else other than investments unwise or detrimental to the economy while others believe that consumer credit is beneficial to the economy. Historically, across many cultures, being in personal debt was considered almost immoral. More recently, an alternative analysis might view consumer debt as a way to increase domestic production, on the grounds that if credit is easily available, the increased demand for consumer goods should cause an increase of overall domestic production. The permanent income hypothesis suggests that consumers take debt to smooth consumption throughout their lives, borrowing to finance expenditures (particularly housing and schooling) earlier in their lives and paying down debt during higher-earning periods.

Both domestic and international economists have supported a recent upsurge in South Korean consumer debt, which has helped fuel economic expansion. On the other hand, credit card debt is almost unknown just across the sea in Japan and China, one because of long standing historical biases against personal debt, the other because the economy is still underdeveloped. Theoretical underpinnings aside, personal debt is on the rise, particularly in the United States and the UK.

The most common form of consumer debt is credit card debt, payday loans, and other consumer finance, which are often at higher interest rates than long term secured loans, such as mortgages. The interest rate charged depends on a range of factors, including the economic climate, perceived ability of the customer to repay, competitive pressures from other lenders, and the inherent structure and security of the credit product. Rates generally range from 0.25% above base-rate, to well into double figures. Consumer debt can be associated with Predatory lending, although there is much debate as to what exactly constitutes predatory lending.

Long-term consumer debt is often considered fiscally suboptimal. While some consumer items may be useful investments that justify debt (such as automobiles, which are usually but not always exempted in discussions of consumer debt, and business suits), most consumer goods are not. For example, incurring high-interest consumer debt through buying a big-screen television "now", rather than saving for it, can not usually be financially justified by the subjective benefits of having the television early. On the other hand, personal finance advisors encourage a more liberal attitude towards taking on debt if it can be leveraged into a small business or real estate. This higher-risk, possibly high-outcome, "personal-finances-as-a-game" attitude runs counter to the traditional mores of rising slowly through the ranks of a company through discipline and hard work, but may have increasing validity in an age of globalization.

In many countries, the ease with which individuals can accumulate consumer debt beyond their means to repay has precipitated a growth industry in debt consolidation and credit counseling.

Debt allows people and organizations to do things that they would otherwise not be able, or allowed, to do. Commonly, people in industrialized nations use it to purchase houses, cars and many other things too expensive to buy with cash on hand. Companies also use debt in many ways to leverage the investment made in their assets, "leveraging" the return on their equity. This leverage, the proportion of debt to equity, is considered important in determining the riskiness of an investment; the more debt per equity, the riskier. For both companies and individuals, this increased risk can lead to poor results, as the cost of servicing the debt can grow beyond the ability to pay due to either external events (income loss) or internal difficulties (poor management of resources).

Excesses in debt accumulation have been blamed for exacerbating economic problems. For example, prior to the beginning of the Great Depression debt/GDP ratio was very high. Economic agents were heavily indebted. This excess of debt, equivalent to excessive expectations on future returns, accompanied asset bubbles on the stock markets. When expectations corrected, deflation and a credit crunch followed. Deflation effectively made debt more expensive and, as Fisher explained, this reinforced deflation again, because, in order to reduce their debt level, economic agents reduced their consumption and investment. The reduction in demand reduced business activity and caused further unemployment. In a more direct sense, more bankruptcies also occurred due both to increased debt cost caused by deflation and the reduced demand.

It is possible for some organizations to enter into alternative types of borrowing and repayment arrangements which will not result in bankruptcy. For example, companies can sometimes convert debt that they owe into equity in themselves. In this case, the creditor hopes to regain something equivalent to the debt and interest in the form of dividends and capital gains of the borrower. The "repayments" are therefore proportional to what the borrower earns and so can not in themselves cause bankruptcy. Once debt is converted in this way, it is no longer known as debt.

Arguments against debt

Some argue against debt as an instrument and institution, on a personal, family, social, corporate and governmental level. Islam forbids lending with interest even today, while the Catholic Church allowed it from 1822 onwards, and the Torah states that all debts should be erased every 7 years and every 50 years.

Debt will increase through time if it is not repaid faster than it grows through interest. This effect may be termed usury, while the term "usury" in other contexts refers only to an excessive rate of interest, in excess of a reasonable profit for the risk accepted.

In international legal thought, odious debt is debt that is incurred by a regime for purposes that do not serve the interest of the state. Such debts are thus considered by this doctrine to be personal debts of the regime that incurred them and not debts of the state.

In an economy with high interest rates, debt will be more costly to a business than more flexible dividends on equity investment. It may be easier for a struggling business to be financed through equity investment as it may be possible to avoid paying a dividend if times are hard.

Levels and flows

Global debt underwriting grew 4.3% year-over-year to $5.19 trillion during 2004. It is expected to rise in the coming years if the spending habits of millions of people worldwide continue the way they do.