The OPSC Odisha Civil Services (OAS/OCS) prelims economy section regularly tests fundamental concepts and the broad structure of the Indian economy. This page covers the definitions, relationships, and classifications that appear in previous year papers, including OPSC 2018.
Basic Concepts
Barter and Money
Definition — Barter Transaction: Goods are exchanged with goods, without the use of money.
Definition — Demand: Demand means demand backed by purchasing power, not mere desire.
Money acts as a medium of exchange and removes the double coincidence of wants — the core problem of barter. Equilibrium price is the price at which supply equals demand; at this price there is neither surplus nor shortage.
Demand and Elasticity
- The law of demand states an inverse relationship between price and quantity demanded.
- A normal demand curve slopes downward, so its slope is negative.
- Zero price elasticity of demand means that whatever the change in price, there is absolutely no change in demand (vertical demand curve).
- Price elasticity of demand depends on (i) the nature of the good and (ii) the availability of close substitutes.
Giffen Goods: Demand can be inversely or positively related to price, depending on the relative strengths of the income and substitution effects. If the income effect is stronger than the substitution effect, demand for the good is positively related to its price.
Utility
According to the law of diminishing marginal utility, as the amount of a good consumed increases, the marginal utility of that good tends to diminish.
Production and Costs
| Concept | Statement |
|---|---|
| Law of Diminishing Returns | When more units of a variable factor are used with fixed factors constant, a point is reached beyond which the marginal product diminishes. |
| Law of Increasing Returns | Means decreasing cost. |
| Production Function | Changes whenever the relevant technology changes. |
| Price of a Commodity | Is the same as average revenue. |
Total Product & Marginal Product:
- When total product reaches its maximum → marginal product becomes zero.
- When total product begins to decline → marginal product becomes negative.
Market Structures
Market structures are defined by the number of sellers and the nature of the product.
| Market Structure | Key Characteristic |
|---|---|
| Perfect competition | Many producers selling similar products |
| Monopoly | Only one producer selling one commodity |
| Monopolistic competition | Many producers selling differentiated products (e.g., toothpaste) |
| Oligopoly | Few producers selling similar or almost similar products |
| Duopoly | Two sellers |
| Bilateral monopoly | One seller and one buyer |
- In a monopoly, the firm's demand curve is the market demand curve, and the marginal revenue curve lies below the average revenue curve.
- In perfect competition, the average revenue and marginal revenue curves of the firm are perfectly elastic.
- In the long run, a competitive firm earns only normal profits.
- When marginal revenue is positive → total revenue increases with output.
- When marginal revenue is zero → total revenue is maximum.
- When marginal revenue becomes negative → total revenue falls with increase in output.
Structure of Indian Economy
Sectors of the Economy
| Sector | Activities |
|---|---|
| Primary | Extraction of natural resources — mining, agriculture, dairy, bee-keeping |
| Secondary | Manufacturing, construction, electricity |
| Tertiary | Services — transport, banking, insurance, call-centre work, tuition |
Common Traps:
- Construction is not part of the service sector — it is secondary.
- Manufacturing does not include real estate industries.
- Bee-keeping is primary, not tertiary.
- Agriculture → primary; Services → tertiary.
More than 50% of the working population in India depends on the primary sector.
Organised and Unorganised Sectors
The unorganised sector is characterised by small and scattered units which are largely outside the control of the government. It is also marked by more currency transactions. The organised sector is registered and regulated.
Public Sector, Private Sector and Mixed Economy
- A mixed economy means an economy where there is co-existence of the public sector along with the private sector.
- In socialist economies, all productive resources are owned and controlled by the government.
- In a capitalist economy, there is private ownership of the means of production.
- A closed economy is one in which neither exports nor imports take place.
Functions of the Public Sector in India:
- To provide public utility resources.
- To build social and economic overhead capital.
- To ensure balanced regional and sectoral growth.
- To pursue egalitarian goals.
Features of a Less Developed Economy
Elements that explain India as a less developed economy include income inequality, a high dependency ratio, and transformations in the banking and financial sector. A low GDP growth rate is not a defining feature in the same way.
Key Economists and Theories
| Economist / Concept | Key Point |
|---|---|
| Adam Smith | Father of Modern Economics; wrote The Wealth of Nations |
| John Maynard Keynes | From England; Keynesian economics emphasises expenditure; coined the Paradox of Thrift |
| Simple Keynesian Theory | Slope of the aggregate consumption curve against income is positive; income and consumption are directly related |
| Minimum payment of a factor | Called rent |
| Gresham's Law | Comes into operation when good money is hoarded |
| Geoffrey Kay | Capital created underdevelopment not because it exploited the underdeveloped world, but because it did not exploit it enough |
| Word 'Economics' | Taken from Greek |
Keynesian theory advocates a mixed economy with a large role of government and public sector. Keynes did not support the Laissez-Faire policy of capitalism.
Criticisms of Rostow's Theory of Economic Growth:
- Much available data contradicts his thesis about the take-off stage.
- There is no explanation of why growth occurs after take-off.
- His hypothesis of stages of growth is difficult to test empirically.
OAS vs UPSC: What to Focus On
| Aspect | OAS Prelims | UPSC |
|---|---|---|
| Question style | Direct, factual definitions and matches | Analytical application with current issues |
| Example | OPSC 2018 asked on Rostow's theory and primary activity | Concepts integrated with policy and economy-wide trends |
| Preparation | Memorise standard definitions and classifications; practise match-the-following and statement-based questions | Understand linkages and apply to unseen contexts |
The OPSC has also asked about Gresham's Law in 2018, so pay attention to such laws and their exact conditions.
Odisha-Specific Angles
OAS aspirants should be ready to apply these concepts to Odisha's economy. The state's heavy dependence on agriculture and mining makes the primary sector's role in employment particularly relevant. Questions may ask you to identify primary activities in the Odisha context or classify sectors. Always verify current figures from the official Odisha Economic Survey.
Practice Questions
Q1. Barter transaction means:
(a) goods are exchanged with gold (b) coins are exchanged for goods (c) money acts as a medium of exchange (d) goods are exchanged with goods
Ans: (d) — Barter is the direct exchange of goods for goods, without money.
Q2. Who coined the concept of 'Paradox of Thrift'?
(a) Adam Smith (b) Alfred Marshall (c) John Maynard Keynes (d) Paul A. Samuelson
Ans: (c) — Keynes introduced the Paradox of Thrift.
Q3. The value of the slope of a normal demand curve is:
(a) positive (b) negative (c) zero (d) infinity
Ans: (b) — A normal demand curve slopes downward, giving a negative slope.
Q4. Zero price elasticity of demand means:
(a) whatever the change in price, there is absolutely no change in demand (b) for a small change in price, there is a small change in demand (c) for a small change in price, there is a large change in demand (d) for a large change in price, there is a small change in demand
Ans: (a) — Perfectly inelastic demand; the demand curve is vertical.
Q5. Which one is a primary activity?
(a) Mining (b) Processing (c) Fabrication (d) Manufacturing
Ans: (a) — Mining involves extraction of natural resources.
Q6. Which economic activity cannot be included in the tertiary sector?
(a) Working in a call-centre (b) Tuition occupation (c) Bee-keeping (d) Banking
Ans: (c) — Bee-keeping is an agricultural (primary) activity.
Q7. A market in which there are a few large firms is called:
(a) Duopoly (b) Competition (c) Oligopoly (d) Monopoly
Ans: (c) — Oligopoly is dominated by a few large firms.
Q8. A 'closed economy' is an economy in which:
(a) the money supply is fully controlled (b) deficit financing takes place (c) only exports take place (d) neither exports nor imports take place
Ans: (d) — A closed economy has no international trade.
Q9. Gresham's Law comes into operation when:
(a) good money is hoarded (b) good money is melted (c) good money is exported (d) good money is hoarded, melted and exported
Ans: (a) — Bad money drives out good money when good money is hoarded.
Q10. Which of the following is a fixed cost?
(a) Expenditure of raw material (b) Traffic expenditure (c) Expenditure on machines (d) Labour wage
Ans: (c) — Expenditure on machines does not vary with output.