Macro economic study since micro economy studies behavior of a particular firm where as macro economy studies about the industry where industry means summation of all individual firms of the economy.

An indifference schedule is a list of combination of two commodities, the list being so arranged that a consumer is indifferent to the combinations, preferring none of them to any of other.

A stock or supply of money, materials, staff, and other assets that can be drawn on by a person or organization in order to function effectively.

Main sources of the secondary data can be classified into two groups :
1. Published sources :
a) Government Publications
(b) Semi-government Publications
(c) International Publications
(d) Private Publications
(e) Research Publications
2. Unpublished sources : Secondary Data can be obtained from unpublished sources, because all statistical material is not always published. Studies made by research institutions, scholars etc. can be important sources of secondary data.

Scarcity means shortage of goods and resources in relation to their demand.

  The quantity of the Good Y sacrificed

The central problems of an economy can be defined as the problems faced by every economy in the world and they are particularly related with problem of choice, because of scarce resources, alternative uses of resources and unlimited human wants.

Central problems are divided into three categories -

1. What to produce  this problem is related with problem of choice of producing wether capital goods or consumer goods.

2. How to produce this problem is related with problem of choosing tecnique of production. The choice is to be made between capital intensive technique of production or labour intensive technique of production.

3. For whom to produce this problem is related with problem of choosing for which group of people goods are to be produced. Wether production is to be done for richer section of society or poorer section of society. 

(a) Marginal Opportunity Cost. MOC of a particular good (say wheat) along a PP curve is the amount of the other good (say tanks) which is sacrificed to produce an additional unit of that particular good. The rate of this sacrifice is called marginal opportunity cost of the expanding good. Rate of sacrifice is technically termed as marginal rate of transformation (MRT).
MRT is the ratio of units of one good (say, tanks) that needs to be sacrificed to produce one more unit of the other good (say, wheat). Symbolically :


 

 A close look at the above table reveals that as production of wheat is increased, its marginal opportunity cost (MOC) in terms of tanks goes on increasing, i.e., MRT is rising. For example, when society moves from combination A to B, it sacrifices 1 (= 15 - 14) thousand tanks to produce 1 (= 1 - 0) lakh ton of wheat. Thus MOC of 1 lakh ton of wheat is 1 thousand tanks in the beginning, i.e., MRT = 1 : 1. Likewise in combinations C, D, E and F, MOC of producing 1 lakh ton of additional wheat is 2 (= 14 -12) thousand, 3(= 12 - 9) thousand, 4(= 9 - 5) thousand and 5(= 5 - 0) thousand tanks respectively. In short for every unit increase in production of wheat, more and more tanks are to be sacrificed, i.e., marginal opportunity cost, i.e., MRT goes on increasing. But why does MOC increase? Following are its two main reasons.

(b) Reasons for increasing marginal opportunity cost (or MRT)

(i) Operation of law of diminishing returns (or increasing cost). According to this law, if more and more units of a good are to be produced, the additional units will require more and more of factors units, i.e., cost of production of additional units of the good will increase.

(ii) Transferring resources from more productive to less productive uses. Various resources are specialised in production of different goods. When factors (resources) which are specialised for production of a particular good (say, workers manufacturing tanks) are transferred to the production of another good (say, production of wheat) for which they are less productive, some productivity is lost. Therefore, more of such resources (say workers) are needed to produce an additional unit of other good. This implies increase in marginal opportunity cost making the PP curve concave in shape.