Meaning of Supply .

 Supply.... 

In common sense, supply is same as sale. Quantity sold is said to be quantity supplied. But in economics, quantity oa a particular commodity that would be offered for sale at all possible prices during a particular period of time is called supply. The term ' offered for sale' means ability to sale and willingness to sale. Both are most essential to be a supply. 

Determinants of Supply... 

The quantity supplied of a particular commodity either increases or decreases with the passes of time due to change in several factors which are called determinants of supply. Some common determinants which affect the quantity supplied of various commodities are as follows:

1. Price of goods and services: Price of the commodity is considered as main determinant of the quantity supplied in the market. Other things being equal, when price rises, supply also rises and vice versa. 

2. Price of related commodities: In case of substitute goods, when the price of a commodity increases the supply of its substitute goods decreases. For example: increase im price of Coca-Cola decreases the supply of Pepsi. Similarly, in case of complementary goods, when the price of a commodity increases, the supply of its complementary goods increases and vice versa other things remaining the same. 

3. Objective of a firm: Objective of a firm is of two types. If the objective of a firm is profit making, then the supply of a commodity decreases at constant price. But if the objective of a firm is service providing, then the quantity supplied increases even at constant price. 

4. Number of firms in the market: If there are number of firms in the market, the quantity supplied of a commodity also increases and vice versa other factors remaining the same. 

5. Price of factors of production: If the price of factors of production increases, the cost price of the commodity also increases. Due to this, the quantity supplied of a commodity also decreases and vice versa, other factors remaining the same. 

6. Tax and subsidy policy of government: The imposition of heavy taxes on inputs leads to increase in the cost of production and consequently supply is reduced and vice versa other factors remaining the same. Conversely, subsidies lower costs and increases supply and vice versa whatever be the price. 

7. Development of technology: The development of technology helps to lower the cost of production and the supply of a commodity in the market increases, other factors remaining the same. 

Supply function.... 

We know that there is a relationship between quantity supplied of a particular commodity and its various determining factors which is defined as supply function. In other words, the technical or functional relationship between quantity supplied of a commodity and its various determining factors is defined as supply function. It is expressed as follows: 

    Qs= F(P, Py, Nf, Of, Ts , Dt, Di, Nfa... etc.) 

Where, 

Qc = quantity supplied for a particular commodity

F = functional relationship

P = price of commodity

Py = price of related commodities

Nf = number of firms in the market

Of= objective of firm

Ts = tax and subsidy policy of government

Dt = development of technology

Di = development of infrastructure

Nfa = natural factors

     Out of various determining factors, price of a commodity is considered as an important determining factor of supply. Therefore, in short, supply is the function of price, other factors remaining the same. 

Therefore, Qs = F(P) , if other factors remaining the same.