Parity Price

The term "parity" refers to equality. Thus, parity price is a price for an asset that is directly linked to another price. Examples of parity price are:

1. Convertibles - the price at which a convertible security equals the value of the underlying stock.
2. Options - when an option is trading at its intrinsic value ("trading at parity").
3. International parity - official rates for a currency in terms of other pegged currencies, typically the U.S. dollar.
4. Commodities - a commodity's price dependent on a composite of prices during a period of time, usually the most recent 10-year period.
5. Listed parity - situation when all parties involved are of equal standing and priority.

Investopedia Says:
Parity price is commonly used in the context of convertible securities and often referred to as "conversion parity price" or "market conversion price". It is the price an investor effectively pays to exchange or convert a convertible security into common stock and is equal to the price of the convertible security divided by the conversion ratio (the number of shares that the convertible can be converted into). Conversely, in the case of common stock, it is calculated by dividing its market value by its conversion ratio.

In commodities, you can think of parity price as the purchasing power of a particular commodity relative to a farmer's expenses such as wages, interest on debt, equipment, taxes and so forth. The Agricultural Adjustment Act of 1938 states that the parity price formula is "average prices received by farmers for agricultural commodities during the last ten years and is designed to gradually adjust relative parity prices of specific commodities". If the parity price for a commodity is not sufficient enough for a farm operator to support his or her family and operate their business then the government could step in and support prices through direct purchases, or the issuance of non-recourse loans to farmers.

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Price for a commodity or service that is pegged to another price or to a composite average of prices based on a selected prior period. As the two sets of prices vary, they are reflected in an index number on a scale of 100. For example, U.S. Farm prices are pegged to prices based on the purchasing power of farmers in the period from 1910 to 1914. If the parity ratio is below 100, reflecting a reduction in purchasing power to the extent indicated, the government compensates the farmer by paying a certain percentage of parity, either in the form of a direct cash payment, in the purchase of surplus crops, or in a Nonrecourse Loan.

The concept of parity is also widely applied in industrial wage contracts as a means of preserving the real value of wages.

A price paid to American farmers that is designed to give them the same real income that they had between 1910 and 1914, a period selected because it was a time of agricultural prosperity.