Index (economics)

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In statistics, economics, and finance, an index is a statistical measure of change in a representative group of individual data points. These data may be derived from any number of sources, including company performance, prices, productivity, and employment. Economic indices track economic health from different perspectives. Examples include the consumer price index, which measures changes in retail prices paid by consumers, and the cost-of-living index (COLI), which measures the relative cost of living over time. [1]

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Influential global financial indices such as the Global Dow, and the NASDAQ Composite track the performance of selected large and powerful companies in order to evaluate and predict economic trends. The Dow Jones Industrial Average and the S&P 500 primarily track U.S. markets, though some legacy international companies are included. [2] The consumer price index tracks the variation in prices for different consumer goods and services over time in a constant geographical location and is integral to calculations used to adjust salaries, bond interest rates, and tax thresholds for inflation.

The GDP Deflator Index, or real GDP, measures the level of prices of all-new, domestically produced, final goods and services in an economy. [3] Market performance indices include the labour market index/job index and proprietary stock market index investment instruments offered by brokerage houses.

Some indices display market variations.[ definition needed ] For example, the Economist provides a Big Mac Index that expresses the adjusted cost of a globally ubiquitous Big Mac as a percentage over or under the cost of a Big Mac in the U.S. in USD. [4] Such indices can be used to help forecast currency values.[ citation needed ]

Index numbers

An index number is an economic data figure reflecting price or quantity compared with a standard or base value. [5] [6] The base usually equals 100 and the index number is usually expressed as 100 times the ratio to the base value. For example, if a commodity costs twice as much in 1970 as it did in 1960, its index number would be 200 relative to 1960. Index numbers are used especially to compare business activity, the cost of living, and employment. They enable economists to reduce unwieldy business data into easily understood terms.

In contrast to a cost-of-living index based on the true but unknown utility function, a superlative index number is an index number that can be calculated. [1] Thus, superlative index numbers are used to provide a fairly close approximation to the underlying cost-of-living index number in a wide range of circumstances. [1]

Some indexes are not time series. Spatial indexes summarize real estate prices, or toxins in the environment, or availability of services, across geographic locations. Indexes may also be used to summarize comparisons between distributions of data within categories. For example, purchasing power parity comparisons of currencies are often constructed with indexes.

There is a substantial body of economic analysis concerning the construction of index numbers, desirable properties of index numbers and the relationship between index numbers and economic theory.[ citation needed ] A number indicating a change in magnitude, as of price, wage, employment, or production shifts, relative to the magnitude at a specified point usually taken as 100.

Index number problem

The index number problem is the term used by economists to describe the limitation of statistical indexing, when used as a measurement for cost-of-living increases. [7]

For example, in the Consumer Price Index, a reference year's "market basket" is assigned an index number of 100. In 2019 if a market basket price is 55 and the basket were to double the following year, in 2020, then the index would rise to 200. This is done by performing a simple calculation: Dividing the new year market basket price by the reference year's (otherwise known as the base year) price, and subsequently multiplying the quotient by 100.

While the CPI is a conventional method to measure inflation, it doesn't express how price changes directly affect all consumer purchases of goods and services. It either understates or overstates cost-of-living increases. This is the limitation of the CPI that is described as the index number problem.

There is no theoretically ideal solution to this problem. In practice for retail price indices, the "basket of goods" is updated incrementally every few years to reflect changes. Nevertheless, the fact remains that many economic indices taken over the long term are not really like-for-like comparisons and this is an issue taken into account by researchers in economic history.

See also

Related Research Articles

<span class="mw-page-title-main">Inflation</span> Devaluation of currency over a period of time

In economics, inflation is a general increase of the prices of goods and services in an economy. This is usually measured using the consumer price index (CPI). When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reduction in the purchasing power of money. The opposite of CPI inflation is deflation, a decrease in the general price level of goods and services. The common measure of inflation is the inflation rate, the annualized percentage change in a general price index. As prices faced by households do not all increase at the same rate, the consumer price index (CPI) is often used for this purpose.

Purchasing power parity (PPP) is a measure of the price of specific goods in different countries and is used to compare the absolute purchasing power of the countries' currencies. PPP is effectively the ratio of the price of a basket of goods at one location divided by the price of the basket of goods at a different location. The PPP inflation and exchange rate may differ from the market exchange rate because of tariffs, and other transaction costs.

An economic indicator is a statistic about an economic activity. Economic indicators allow analysis of economic performance and predictions of future performance. One application of economic indicators is the study of business cycles. Economic indicators include various indices, earnings reports, and economic summaries: for example, the unemployment rate, quits rate, housing starts, consumer price index, Inverted yield curve, consumer leverage ratio, industrial production, bankruptcies, gross domestic product, broadband internet penetration, retail sales, price index, and changes in credit conditions.

<span class="mw-page-title-main">Consumer price index</span> Statistic to indicate the change in typical household expenditure

A consumer price index (CPI) is a price index, the price of a weighted average market basket of consumer goods and services purchased by households. Changes in measured CPI track changes in prices over time. The CPI is calculated by using a representative basket of goods and services. The basket is updated periodically to reflect changes in consumer spending habits. The prices of the goods and services in the basket are collected monthly from a sample of retail and service establishments. The prices are then adjusted for changes in quality or features. Changes in the CPI can be used to track inflation over time and to compare inflation rates between different countries. The CPI is not a perfect measure of inflation or the cost of living, but it is a useful tool for tracking these economic indicators.

In economics, the GDP deflator is a measure of the money price of all new, domestically produced, final goods and services in an economy in a year relative to the real value of them. It can be used as a measure of the value of money. GDP stands for gross domestic product, the total monetary value of all final goods and services produced within the territory of a country over a particular period of time.

<span class="mw-page-title-main">Big Mac Index</span> Economic index published by The Economist

The Big Mac Index is a price index published since 1986 by The Economist as an informal way of measuring the purchasing power parity (PPP) between two currencies and providing a test of the extent to which market exchange rates result in goods costing the same in different countries. It "seeks to make exchange-rate theory a bit more digestible." The index compares the relative price worldwide to purchase the Big Mac, a hamburger sold at McDonald's restaurants.

A market basket or commodity bundle is a fixed list of items, in given proportions. Its most common use is to track the progress of inflation in an economy or specific market. That is, to measure the changes in the value of money over time. A market basket is also used with the theory of purchasing price parity to measure the value of money in different places.

In economics, nominal value refers to value measured in terms of absolute money amounts, whereas real value is considered and measured against the actual goods or services for which it can be exchanged at a given time. For example, if one is offered a salary of $40,000, in that year, the real and nominal values are both $40,000. The following year, any inflation means that although the nominal value remains $40,000, because prices have risen, the salary will buy fewer goods and services, and thus its real value has decreased in accordance with inflation. On the other hand, ownership of an asset that holds its value, such as a diamond may increase in nominal price increase from year to year, but its real value, i.e. its value in relation to other goods and services for which it can be exchanged, or its purchasing power, is consistent over time, because inflation has affected both its nominal value and other goods' nominal value. In spite of changes in the price, it can be sold and an equivalent amount of emeralds can be purchased, because the emerald's prices will have increased with inflation as well.

The PCE price index (PePP), also referred to as the PCE deflator, PCE price deflator, or the Implicit Price Deflator for Personal Consumption Expenditures by the Bureau of Economic Analysis (BEA) and as the Chain-type Price Index for Personal Consumption Expenditures (CTPIPCE) by the Federal Open Market Committee (FOMC), is a United States-wide indicator of the average increase in prices for all domestic personal consumption. It is benchmarked to a base of 2012 = 100. Using a variety of data including U.S. Consumer Price Index and Producer Price Index prices, it is derived from the largest component of the GDP in the BEA's National Income and Product Accounts, personal consumption expenditures.

A price index is a normalized average of price relatives for a given class of goods or services in a given region, during a given interval of time. It is a statistic designed to help to compare how these price relatives, taken as a whole, differ between time periods or geographical locations.

Substitution bias describes a possible bias in economic index numbers if they do not incorporate data on consumer expenditures switching from relatively more expensive products to cheaper ones as prices changed.

The Penn effect is the economic finding that real income ratios between high and low income countries are systematically exaggerated by gross domestic product (GDP) conversion at market exchange rates. It is associated with what became the Penn World Table, and it has been a consistent econometric result since at least the 1950s.

<span class="mw-page-title-main">United States Consumer Price Index</span> Statistics of the U.S. Bureau of Labor Statistics

The United States Consumer Price Index (CPI) is a set of various consumer price indices published monthly by the U.S. Bureau of Labor Statistics (BLS). The most commonly used are the CPI-U and the CPI-W, though many alternative versions exist. The CPI-U is the most popular measure of consumer inflation in the United States.

The international dollar, also known as Geary–Khamis dollar, is a hypothetical unit of currency that has the same purchasing power parity that the U.S. dollar had in the United States at a given point in time. It is mainly used in economics and financial statistics for various purposes, most notably to determine and compare the purchasing power parity and gross domestic product of various countries and markets. The year 1990 or 2000 is often used as a benchmark year for comparisons that run through time. The unit is often abbreviated, e.g. 2000 US dollars or 2000 International$.

This page lists details of the consumer price index by country

The effective exchange rate is an index that describes the strength of a currency relative to a basket of other currencies. Suppose a country has trading partners and denote and as the trade and exchange rate with country respectively. Then the effective exchange rate is calculated as:

The measurement of economic worth over time is the problem of relating past prices, costs, values and proportions of social production to current ones. For a number of reasons, relating any past indicator to a current indicator of worth is theoretically and practically difficult for economists, historians, and political economists. This has led to some questioning of the idea of time series of worth having any meaning. However, the popular demand for measurements of social worth over time have caused the production of a number of series.

Inflation rate in India was 5.5% as of May 2019, as per the Indian Ministry of Statistics and Programme Implementation. This represents a modest reduction from the previous annual figure of 9.6% for June 2011. Inflation rates in India are usually quoted as changes in the Wholesale Price Index (WPI), for all commodities.

The United States Chained Consumer Price Index (C-CPI-U), also known as chain-weighted CPI or chain-linked CPI is a time series measure of price levels of consumer goods and services created by the Bureau of Labor Statistics as an alternative to the US Consumer Price Index. It is based on the idea that when prices of different goods change at different rates, consumers will adjust their purchasing patterns by purchasing more of products whose relative prices have declined and fewer of those whose relative price has increased. This reduces the cost of living reported, but has no change on the cost of living; it is simply a way of accounting for a microeconomic "substitution effect." The "fixed weight" CPI also takes such substitutions into account, but does so through a periodic adjustment of the "basket of goods" that it represents, rather than through a continuous adjustment in that basket. Application of the chained CPI to federal benefits has been controversially proposed to reduce the federal deficit.

This glossary of economics is a list of definitions of terms and concepts used in economics, its sub-disciplines, and related fields.

References

  1. 1 2 3 Turvey, Ralph. (2004) Consumer Price Index Manual: Theory And Practice. Page 11. Publisher: International Labour Organization. ISBN   92-2-113699-X.
  2. ↑ "Index Investing: What Is An Index?". www.investopedia.com. 1 December 2003. Retrieved 23 September 2016.
  3. ↑ "GDP deflator and measuring inflation". www.politonomist.com. Archived from the original on 17 January 2009. Retrieved 23 September 2016.
  4. ↑ "Currency Converter | Foreign Exchange Rates | OANDA". www.oanda.com. Retrieved 24 September 2016.
  5. ↑ Diewert, W. E., "Index Numbers", in Eatwell, John; Milgate, Murray; Newman, Peter (eds.), The New Palgrave: A Dictionary of Economics, vol. 2, pp. 767–780
  6. ↑ Moulton, Brent R.; Smith, Jeffrey W., "Price Indices", in Newman, Peter; Milgate, Murray; Eatwell, John (eds.), The New Palgrave Dictionary of Money and Finance, vol. 3, pp. 179–181
  7. ↑ Baumol, William J.; Blinder, Alan S. (14 June 2011). Macroeconomics : principles & policy (12th ed.). South Western, Cengage Learning. p. 125. ISBN   978-0-538-45365-3.

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