Stonier and Hague, "Elasticity of demand is  therefore a technical term used by the Economists to describe the degree of responsiveness of the quantity demand for a commodity to a change in its price" .

(i) Colonialism refers to a system of political and social relations between two countries, of which one is the ruler and the other is its colony.
(ii) The ruling country not only has political control over the colony, but it also determines the economic policies of the subjugated country.

(i) According to classical theory the equilibrium interest rate is determined by the intersection of demand and supply curves
(ii) Demand for money refers to investment and supply of money refers to savings.
(iii) S = I

Mathematically the supply function is
Q_s = f (P_x' P_I' P_f, T, O, E)
Where Qs = Quantity supplied of x commodity
P_x = Price of x Commodity
P_r = Price of related goods
P_f = Price of factors of production
T = Technology
O = Objective of the producer
E = Expected Price of the commodity.

Q_d=f (P_x) where Q_d stands for Quantity demand of a commodity and P_x is the price of that commodity

Developed economies are those countries which are industrialised utilized their resources efficiently and high per capita income.

(i) All costs that vary with output, together with the costs of administration are known as prime cost.
(ii) In short, prime cost = variable costs + cost of administration.

Gross State Domestic Product refers to the total money value of all goods and services produced annually in the state.

(i) In deductive method we move from general to particular.
(ii) It is also called as analytical (or) abstract method.

(i) Interest is a payment made by a borrower to the lender for the money borrowed.
(ii) It is the price paid for the use of capital.

Banking, insurance, energy, transport and communications fall under tertiary sector.i.e., services.
Banking: In Tamil Nadu, Nationalised banks account for 52% with 5,337 branches, Private Commercial Banks 30% (3,060) branches, State Bank of India and its associates 13(1,364), Regional Rural Banks 5% (537) branches and the remaining 22 foreign bank branches.
Education:
(a) School Education: Tamil Nadu is grouped among high Gross Enrolment Ratio (GER) States. It ranks third next only to Kerala (81%)and Himachal Pradesh (74%). The all India average is 43%and the world average is 59%.
(b) Higher Education: In Gross Enrolment Ratio under higher education (Tertiary level) Tamil Nadu continues to be at the top level well ahead of other states. The GER is 46.9% in Tamil Nadu which is far higher against national average and all other States.
Tamil Nadu has 59 Universities, 40 Medical colleges, 517 Engineering colleges, 2,260 Arts and Science colleges, 447 Polytechnics and 20 dental colleges. Tamil Nadu produces nearly four lakh engineering and polytechnic students every year, the highest in the country.
Educational Loans: As far as educational loans disbursed by Public Sector Banks under priority sector are concerned, 20.8% of the total amount was disbursed in Tamil Nadu between 2013-14 and 2015-16.
Health: Tamil Nadu has a three-tier health infrastructure comprising hospitals, primary health centres, health units, community health centres and sub-centres. As of March 2015, the State had 34 district hospitals, 229 sub-divisional hospitals, 1,254 primary health centres, 7,555 Sub-centres and 313 community health centres.
Communication: Maharashtra has the highest number of internet subscribers in the country at 29.47 million, followed by States like Tamil Nadu, Andhra Pradesh and Karnataka.
Transport: Tamil Nadu has a well established transportation system that connects all parts of the State.
(a) Road: There are 28 national highways in the State, covering a total distance of 5,036 km. The State has a total road length of 167,000 km, of which 60,628 km are maintained by Highways Department. It ranks second in India with a share of over 20% in total road projects under operation in the public-private partnership (PPP) model.
(b) Air: Tamil Nadu has four major international airports. Chennai International Airport is currently the third largest airport in India after Mumbai and Delhi. Other international airports in Tamil Nadu include Coimbatore International Airport, Madurai International Airport and Tiruchirapalli International Airport. It also has - domestic airports at Tuticorin, Salem, and Madurai which connect-several parts of the country.
(c) Ports: Tamil Nadu has three major ports; one each at Chennai, Ennore, and Tuticorin, as well as one intermediate port in Nagapattinam, and 23 minor port.

Differential calculus measures the rate of change of functions. In Economics it is also necessary to reverse the process of differentiation and find the function F(x) whose rate of change has been given. This is called integration. The function F(x) is termed an integral or anti-derivative of the function f(x) The integral of a function f(x) is expressed mathematically as \(\int { f\left( x \right) dx } =F(x)+C\)
Here the left hand side of the equation is read "the integral of f(x) with respect to x" The symbol +" is an integral sign, f(x) is integrand, C is the constant of integration, and F(x)+c is an indefinite integral. It is so called because, as a function of x, which is here unspecified, it can assume many values.

(i) During the British rule stunned the growth of Indian enterprise.
(ii) The economic policies of British checked and retarded capital formation in India.
(iii) Indian agriculture sector became stagnant and deteriorated.
(iv) The British rule in India led the collapse of handicraft industries.
(v) The drain of wealth financed capital development in Britain.

The supply of loanable funds depends upon the following four sources.
(i) Savings (S)
(ii) Bank Credit (BC)
(iii) Dis hoarding (DH)
(iv) Disinvestment (DI)
(i) Savings (S):
1. Supply of loanable funds comes form savings.
2. Savings may be of two types.
They are
(i) "ex-ante savings" and
(ii) "ex-post savings".
(ii) Bank Credit (BC):
1. Commercial banks create credit and supply of loanable funds to the investors.
(iii) Dishoarding (DH):
1. Dishoarding means bringing out the hoarded money into use.
2. It constitutes a source of supply of loanable funds.
(iv) Disinvestment (DI):
1. Disinvestment is the opposite of investment.
2. Not providing sufficient funds for depreciation of equipment.
3. All the four sources of supply of loanable funds vary directly with the interest rate.

Long run equilibrium of the firm and group equilibrium:
(i) In the short run under monopolistic competition, the firm earns supernormal profit or loss.
(ii) But in the long run, the entry of new firms will wipe out supernormal profit.
(iii) And the loss experienced by existing firms, monopolists leaving the industry.
(iv) Hence, the firm will earn the only normal profit in the long run.
(v) In the long run, AR curve is more elastic or flatter due to plenty of substitutes available.

(vi) At Point E the firm achieves the equilibrium where MC = MR.
(vii) OP - Price, OM - Output
(viii) MQ - Average Cost, M = Average Revenue
\(\therefore\) MQ = MQ (AR = AC)
(ix) It means a firm earn the only normal profit in the long run.

(i) Monetary reforms aimed at doing away with interest rate distortions and rationalizing the structure of lending rates.
(ii) The new policy tried in many ways to make the banking system more efficient.
(a) Reserve Requirements:
(i) In mid-1991, SLR and CRR were very high.
(ii) It was proposed to cut down the SLR from 38.5% to 25% within a time span of three years.
(b) Interest rate Liberalisation :
(i) Earlier, RBI controlled the rates payable on deposits of different maturities.
(ii) The rates which could be charged for bank loans which varied according to the sector, use and size of the loan.
(iii) Earlier, it was longer term deposits after the liberalisation it was progressively extended to deposits of shorter maturity.
(c) Greater Competition:
(i) Among public sector, private sector, and foreign banks and elimination of administrative constraints.
(ii) Banks were given freedom to relocate branches.
(iii) Bank branch licensing policy in order to rationalize the existing branch network.
(iv) Guidelines for opening new private sector bank.
(v) New accounting norms regarding classification of assets and provisions of bad debts were introduced for Narasimhan Committee Report.

People related problems:
The problems related to individuals and their standard of living consist of illiteracy, lack of technical know how, low level of confidence, dependence on sentiments, and beliefs.
Agriculture related:
1. Lack of expected awareness, knowledge, skill and attitude.
2. Unavailability of inputs
3. Poor marketing facility.
4. Insufficient extension staff and services.
5. Multidimensional tasks to extension personnel.
6. Small size of land holding.
7. Sub-division and fragmentation of landholdings.
8. Absence of infrastructure to work and stay in rural areas.
9. Primitive technology and low adoption of modern technologies
10. Reduced public investment and absence of role for farmers in fixing price for their products.
Infrastructure related:
Poor infrastructure facilities like water, electricity, transport, educational institutions, communication, health, employment, storage facility, banking and insurance are found in rural areas.
Economics related:
(i) There is inability to adopt high cost technology, high cost of inputs, under privileged rural industries, low income, indebtedness and existence of inequality in land holdings and assets.
(ii) Infertile areas, a few absentee landlords own large area and they do not show any interest in improving the performance of agriculture.
Leadership related:
Leadership is in the hands of inactive and incompetent people, self-interest leaders, biased political will, less bargaining power and dominance of political leaders.
Administrative Problems:
There is political interference, lack of motivation, low wages in villages, improper utilization of budget, absence of monitoring and implementation of rural development programmes.
Conclusion: The problems found in rural economy are endless.

Iso and quant are derived from the Greek language, meaning 'equal' and 'quantity'.
Definition:
Isoquant curve is a locus of points representing various combinations of two inputs capital and labour yielding the same output. It is also called equal product curve or product indifference curve.
Properties:
1. The isoquant curve has negative slope:
(i) Capital is being substituted by labour.
(ii) Isoquant has negative slope because of diminishing MRTS.
(iii) Constant MRTS (straight line) and increasing MRTS (concave) are also possible.
(iv) It depends on the nature of isoquant curve

2. Isoquant curve is convex to origin:
The capital substituted per unit of labour goes on decreasing so the isoquant is convex to the origin.

3. Isoquant curves cannot intersect each other:
Point A lies on IQ₁ and IQ₂, Point C lies on IQ₂, showing higher output Point B
lies on IQ₁, showing lower output. C = A, B = A But C > B.


4. Upper isoquant curve represents a higher level of output:
Higher IQ₂ shows higher output 200 units. Lower IQ₁ shows lower output 100 units. IQ₂ means the use of more sectors than IQ₁. Arrow shows increase in output with a right and upward shift of an isoquant curve.

5. Isoquant curve does not touch either x axis or y axis:
In IQ₂ only capital is used and in IQ₁ only labour is used.

Conclusion:
These are the properties of isoquant curves.

Introduction:
(i) Tamil Nadu stands 6th in population (7.21 crores).
(ii) It is higher than the population of U.K, France, Italy, South Africa, Spain, Sri Lanka. 36158871 males & 35980087 females.
Density:
(i) According to 2011 census it is 555.
(ii) Tamil Nadu ranks 12th in density (India 382).
(iii) The districts with highest population are Chennai, Kancheepuram, Vellore & Thiruvallur.
(iv) The districts with lowest population are Perambalur, the Nilgiris, Ariyalur & Theni.
Urbanisation:
(i) Tamil Nadu is the most urbanized state with 48.4% of urban population.
(ii) The state accounts for 9.61% of total urbanites in India against 6% share of total population.
Sex ratio:
(i) The sex ratio is nearing balance (995).
(ii) Tamil Nadu stands next to Kerala & Puducherry.
(iii) The districts with highest sex ratio are the Nilgiris, Thanjavur & Nagapattinam. The districts with lowest sex ratio are Theni & Dharmapuri.
Infant Mortality rate IMR:
The IMR is 17 (per 1000) compared to the national average of 34.
Maternal Mortality Rate MMR:
(i) Tamil Nadu has a good record of controlling MMR.
(ii) It ranks third 79 next to Kerala & Maharashtra against the national average of 159.
Life expectancy at birth:
The life expectancy for males is 68.6 (India 66.4) and for females it is 72.7(India 69.6).
Literacy:
(i) The literacy rate is higher than many states.
(ii) For males it is 86.81% & females 73.86%.
(iii) Districts with highest literacy are Kanyakumari & Chennai.
(iv) Districts with lowest literacy are Dharmapuri & Ariyalur.

Steps of Deductive method:
(i) Have a clear idea of the problem to be inquired.
(ii) Define the technical terms used. Assumptions should be precise.
(iii) Deduce hypotheses from the assumptions.
(iv) Verify hypotheses through direct observation of events and statistical methods.
Steps of Inductive method:
(i) The collected data must be systematically arranged
(ii) Based on the data, conclusions are drawn
(iii) Generalization of the hypothesis.
(iv) Verification of the hypothesis.

Large number of buyers and sellers:
(i) Since there are large number of buyers and sellers each individual buyer or seller buys or sells a very very small quantity of the product found in the market.
(ii) So he has no power to fix the price of the product.
(iii) He is only a price taker.
Homogenous product & uniform price:
(i) All the units of the product are perfectly substitutable - they are of the same size, shape, colour, quality.
(ii) So a uniform price prevails in the market.
Free entry and exit:
(i) In the short run, the very efficient producer can produce the product at a very low cost & earn super normal profit.
(ii) This attracts new firms to enter.
(iii) When there are more firms, supply increases, so price falls.
(iv) Inefficient producer faces loss & so quits the market.
Absence of transport cost:
The prevalence of the uniform price is also due to the absence of the transport cost.
Perfect knowledge of the market:
(i) All buyers and sellers have a thorough knowledge of the quality of the product, prevailing price.
No government intervention:
(i) No government regulation on supply of raw materials & in price determination.

Q	Price Rs	TR	AR	MR
1	5	5	5	5
2	5	10	5	5
3	5	15	5	5
4	5	20	5	5
5	5	25	5	5
6	5	30	5	5

\(A R=\frac{T R}{Q}\)

\( M R=T R_{n}-T R_{n-1}\)

Constant AR & MR (fixed price)
When price remains constant, MR is also constant and AR / MR curves coincide.
Declining AR and MR
When a firm sells large quantities at lower prices both AR & MR will fall but the fall in MR will be steeper than the fall in AR.

Q	AR	TR	MR
1	10	10	10
2	9	18	8
3	8	24	6
4	7	28	4
5	6	30	2
6	5	30	0
7	4	28	-2

(i) MR is lower than AR.
(ii) Both AR and MR slope downwards.
(iii) MR divides the distance between AR curve and axis into 2 equal parts.
(iv) The decline in AR need not be a straight line or linear.
(v) If the prices are declining with the increase in quantity sold, the AR can be nonlinear, taking a shape of concave or convex to the origin.

Introduction:
(i) Jawaharlal Nehru one of the chief builders of modern India was the first Prime Minister of Independent India.
(ii) He was a great patriot, thinker and statesman.
Democracy and secularism:
(i) Nehru believed in democracy, free speech, civil liberty, adult franchise, the Rule of law and Parliamentary democracy.
(ii) He favoured secularism.
(iii) Secularism means equal respect for all religions. In our country we have Hinduism, Islam, Christianity, Buddhism, Jainism, Sikhism and so on.
(iv) But there is no domination by religious majority.
Planning:
(i) Nehru introduced planning in our country.
(ii) Planning was linked with industrialisation and self-reliance.
(iii) Nehru contributed to the advancement of science, research, technology and industrial development.
(iv) Many IITs and Research Institutions were established.
Democratic socialism:
(i) Nehru wanted a socialistic pattern of society.
(ii) His socialism is democratic socialism.
Conclusion:
(i) Nehru's views on economics and social problems are found in his innumerable speeches and in the books he wrote.

x = 100 - p - p²
\(\frac { dx }{ dp } =-1-2p\)
Elasticity of demand ղ_d = \(-\frac { p }{ x } \frac { dx }{ dp } =\frac { -p\left( -1-2p \right) }{ 100-p-{ p }^{ 2 } } =\frac { p+2{ p }^{ 2 } }{ 100-p-{ p }^{ 2 } } \)
When p = 5, ղ_d = \(\frac { 5+50 }{ 100-5-25 } =\frac { 55 }{ 70 } =\frac { 11 }{ 14 } \)

(i) Biswajeet Guha has stated that the calculation of HDI neglected many important aspects of human development.
(ii) He has created four indices of HDI as HDI₁, HDI₂, HDI₃, and HDI₄. HDI₁ is based on UNDP methodology as given in Human Development Report.
(iii) He has enlarged the scope of HDI by adding three more dimensions such as quality of life, poverty eradication, and urbanization.
(iv) Various countries including India are continuously making efforts to improve and enlarge the scope of available statistical information.

Market Demand for a commodity:
The market demand curve for a commodity is derived by adding the quantum demanded of the commodity by all the individuals constituting the market. In the diagram, the final market demand curve represents the addition of the demand curve of the individuals A, B and C at the same price. When Price is rs.3, the Market demand is 2 + 2 + 4 = 8
When Price is rs. 1 the Market demand is 6 + 8 + 8 = 22
As in the case of individual demand schedule the Market Demand Curve is at a price, at a place and at a time.
  

Introduction: Goods and services satisfy human wants. Goods also called "Products", "Commodities", "things" etc.
Types of Goods
1. Free and Economic Goods: Free goods are available in nature and in abundance. They do not command a price in the market: (Ex) Air, Sunshine. Economic goods common a price in the market. They are scarce in relation to supply (Ex) T.V, Furniture.
2. Consumer goods and capital goods: Consumer goods directly satisfy human wants (Ex) Table, Chair. Capital goods also called Producers goods do not directly satisfy the consumer wants. They help to produce consumer goods. (Ex) Machinery.
3. Perishable goods and durable goods: Perishable goods are short-lived. Their life span is limited (Ex) Fish, Fruits. Durable and semi-durable goods have a little longer life time than the perishable goods (Ex) TV, Table.

1. Monopoly Profit
2. Windfall Profit
3. Profit as functional reward

(i) It is a public sector financial institutions.
(ii) It provides loans at low rates to micro finance institutions.
(iii) And also provides credit to non-banking financial institution, micro, small and medium enterprises.
(iv) It was launched on 8th April 2015.
(v) Mostly individual proprietorships running small manufacturing trading or services activities.
(vi) Most of these are owned by people belonging to scheduled caste, scheduled tribe (or) other backward classes.
(vii) MUDRA was started specifically for financing these units.

(i) RRBs came into existence in 1975.
(ii) They develop the rural economy by providing credit and other facilities to the small and marginal farmers, agricultural labourers, artisans and small entrepreneurs.
(iii) RRBs are set up by the joint efforts of the Centre and State governments and commercial banks.
(iv) At present there are 64 RRBs.
(v) The RRBs confine their lending only to the weaker sections and their lending rates are at par with the prevailing rate of co-operative societies.

(i) Tamil Nadu is the largest textile hub of India.
(ii) It is known as the "Yarn Bowl' of India with 41% of India's cotton yarn production.
(iii) It provides employment to 35 million people, contributing 4% of GDP and 35% of gross export earnings.
(iv) From spinning to garment manufacturing the entire textile production chain facilities are in Tamil Nadu.
(v) Coimbatore, Tirupur, Erode, Dindigul & Karur have the majority of spinning mills manufacturing cotton/polyester/ blended yarn.
(vi) Yarn is exported to China, Bangladesh, Tiruppur (knitting city) exports garments worth USD 3 billion. Karur is famous for textile manufacturing.
(vii) Erode is the main cloth market in south India for retail & wholesale ready-mades.

(i) In duopoly there are only two sellers.
(ii) Each seller is fully aware of his rival's motive and actions.
(iii) Both sellers may collude.
(iv) They may enter into cut-throat competition.
(v) There is no product differentiation.
(vi) They fix the price to get maximum profit.

(i) In the long run all factors of production become variable.
(ii) The size of the firm can be increased.
(iii) There are no fixed inputs in the long run

LAC = LTC/Q
(iv) It is the locus of points denoting the least cost curve of producing the corresponding output.
(v) The LAC curve is called as 'Plant curve' or Boat shape curve or planning curve or envelope curve.