Demand

The need or desire for a good, service, or asset among consumers at a given price. The amount of demand at a given price is determined by supply and the availability of similar or replacements goods and services, among other factors. While demand for some staple products is relatively constant regardless of price, most of the time the price has a large influence on the level of demand. Demand for a good or service tends to increase as its price decreases. See also: Law of supply and demand, Demand curve.

demand

the amount of a product which is purchased at a particular price at a particular point in time. A demand curve is a line showing the relationship between the price of a product and the quantity demanded per time period over a range of possible prices. Demand curves are usually downward sloping, indicating that as the price of the product falls, more is demanded. The extent to which the demand for a product will increase as price falls (and the extent to which demand will drop if the price rises) depends on the product's price-ELASTICITY OF DEMAND. The demand for a product, however, is determined also by a variety of non-price factors. A demand function attempts to incorporate all the factors that have a statistically. significant influence on demand for example, consumers' incomes, the prices of substitute products, advertising, etc. Demand curves will shift if any of these factors change over time.

In practice, firms are unable to derive definitive demand curves because of incomplete information. For this reason many firms use a COST-BASED PRICING formula for determining prices, but allow for the influence of demand by varying the profit mark-up (see DEMAND-BASED PRICING, COMPETITION-BASED PRICING).

There are various methods a firm can use to ‘forecast’ demand, including time series analysis, barometric indicators and econometric models. See SALES FORECASTING.

demand

effective demand

the WANT, need or desire for a product backed by the money to purchase it. In economic analysis, demand is always based on ‘willingness and ability to pay’ for a product, not merely want or need for the product. CONSUMERS’ total demand for a product is reflected in the DEMAND CURVE. Compare SUPPLY.

Collins Dictionary of Economics, 4th ed. © C. Pass, B. Lowes, L. Davies 2005

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References in periodicals archive

Floating aerators satisfy the biological oxygen demand by mixing oxygen from the air into pond water.

Waste water ponds

The water parameters used for the Sual power-plant surface and groundwater quality monitoring program include temperature, pH level, dissolved oxygen, total suspected solid (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), phosphates, hexavalent chromium, dissolved copper, total metals such as lead, manganese, cadmium, arsenic, iron, zinc, mercury, and oil and grease.

Study verifies Sual power plant not causing water pollution, environmental damage

According to Ravinder Kaur, project director at IARI, the mechanism cleans the waste water by 99 per cent, biological oxygen demand ( BOD) by 87 per cent, nitrates by 95 per cent, sulphates by 90 per cent and heavy metals like iron by 99 per cent, chromium by 85 per cent and lead by about 81 per cent.

Sewage water made fit for irrigating fields

Key words: Phycoremediation biological oxygen demand chemical oxygen demand total suspended solids and total dissolve solids.

A COMPARATIVE STUDY ON THE TREATMENT OF INDUSTRIAL AND MIXED EFFLUENT BY ALGAE

The biological oxygen demand ([BOD.sub.5]) test measures the amount of oxygen used by the microorganisms as they utilize the substrate (food) in wastewater.

Advanced technology like reverse osmosis in tannery effluent treatment to enhance the reusing potential of treated effluent at various stages of tanning process

It reduces chemical oxygen demand, biological oxygen demand, suspended solids, fats, oil and grease in wastewater by up to 95 percent.

Micromac Filtration solves white water effluent challenge

Techniques represented included dissolved oxygen (DO) meters, biological oxygen demand and chemical oxygen demand analyzers, nutrient analyzers (nitrates, nitrites and ammonia), total organic carbon analyzers (TOC), pH and ion selective meters, and electrodes, conductivity and resistivity reters, as well as assorted portable and fixed gas analyzers devoted to worker safety.

WEFTEC: submerged opportunities for instruments

* water emissions of heavy metals (Pb, Cd and Hg) and trace organics (dioxins) and biological oxygen demand (BOD) as indicators of the impact on water quality; and

New Computer Model for Integrated Waste Management

"They are effective in treating high biological oxygen demand wastewater, but not so well equipped to treat high chemical oxygen demand levels.

Cleaning up waste naturally: 'low-tech' approaches to VOCs and wastewater treatment have their advantages

A standard aeration process to reduce biological oxygen demand (BOD) and chemical oxygen demand (COD) is used.

Leachate treatment system saves waste disposal costs

Various parameters like Dissolved Oxygen ( DO), Biological Oxygen Demand, Chemical Oxygen Demand, total solids, and pH were analysed to assess the quality of the river.

Idol immersions in Yamuna major cause of concern