CBSE Class 11 Economics

1. Introduction (Statistics)

What is economics and statistics

• Introduction to Statistics for Economics: Meaning, Scope, Functions and Importance – Economics studies how people choose when means are limited and wants are many. Statistics is both a set of number facts (data) and a method: collect, organise, present, analyse and interpret data. In economics it simplifies big facts, allows comparison, shows links between things like price and demand, helps forecast and helps the government plan. It has limits: it studies groups, handles only numbers, and can be misused.

2. Collection, Organisation and Presentation of Data

Collection of data · Organisation of data · Presentation of data

• Collection of Data: Primary and Secondary Sources, Sampling, Census of India and NSSO – Data can be primary (collected first-hand by you) or secondary (already collected by someone else). Primary data comes from personal interviews, mailed questionnaires or telephone interviews. We may study everyone (census) or a small part (sample). Samples can be random or non-random. Results can have sampling errors and non-sampling errors. In India, the Census counts everyone every 10 years, and the NSSO (now NSO) runs sample surveys.
• Organisation of Data: Variables, Classification and Frequency Distribution – Raw data is a heap of numbers with no order. We organise it by classification: grouping similar values. A variable can be discrete (whole jumps, like number of children) or continuous (any value, like height). A frequency distribution puts values into classes and counts how many fall in each. Each class has a lower limit, an upper limit, a width (class interval) and a middle value (class mark). Classes can be exclusive or inclusive.
• Presentation of Data: Tables, Bar and Pie Diagrams, Histogram, Polygon, Ogive and Line Graphs – Data can be presented in words (textual), in tables (tabular) or in pictures (diagrams and graphs). A table has a title, captions, stubs, body and source. Bar diagrams compare values; pie diagrams show parts of a whole with angle = value ÷ total × 360°. For frequency distributions we draw a histogram, a frequency polygon, a frequency curve and ogives. Time series data is shown with an arithmetic line graph.

3. Statistical Tools and Interpretation

Measures of central tendency · Correlation · Index numbers

• Measures of Central Tendency: Mean, Median and Mode with Economic Meaning – An average is one number that stands for a whole group. The arithmetic mean is the total divided by the count; it can be found directly, with an assumed mean, or by step deviation. A weighted mean gives more importance to some items. The median is the middle value after arranging in order; it is not pulled by extreme values. The mode is the most common value. In economics, the mean tells per head income, the median tells the typical income, and the mode tells the most popular size or price.
• Correlation: Scatter Diagram, Karl Pearson's Coefficient and Spearman's Rank Correlation – Correlation tells how two variables move together. It is positive when both rise together, negative when one rises as the other falls, and zero when there is no straight-line pattern. A scatter diagram shows it as a picture. Karl Pearson's coefficient r measures its direction and strength and always lies between −1 and +1. Spearman's rank correlation R uses ranks and works for qualities like beauty or honesty; tied ranks need a small correction.
• Index Numbers: Simple Aggregative Method, WPI, CPI, IIP, Uses and Inflation – An index number is a number that shows how much something (like prices or output) has changed compared with a base year, whose index is 100. The simple aggregative price index is ΣP1 ÷ ΣP0 × 100. Weighted indices give more importance to items bought more. India's key indices are the Consumer Price Index (CPI) for retail prices, the Wholesale Price Index (WPI) for wholesale prices and the Index of Industrial Production (IIP) for factory output. The inflation rate is the percentage rise in a price index over a year.

4. Introduction (Microeconomics)

Introduction to microeconomics

• Introduction to Microeconomics and the Production Possibility Frontier – Microeconomics studies single units like one buyer or one firm; macroeconomics studies the whole economy. Resources are scarce and have other uses, so every economy must decide what, how and for whom to produce. The production possibility frontier (PPF) shows the best mixes of two goods an economy can make with all its resources used fully. Moving along it has an opportunity cost, which usually rises, so the PPF is concave.

5. Consumer's Equilibrium and Demand

Consumer's equilibrium · Demand and its elasticity

• Consumer's Equilibrium: Utility, Budget Line and Indifference Curves – A consumer is in equilibrium when she gets the most satisfaction from her fixed income at given prices, and has no reason to change her purchases. By utility analysis, with one good she buys until MU (in rupees) = price; with two goods MUx/Px = MUy/Py. By indifference curve analysis, the best bundle is where the budget line just touches the highest indifference curve: MRS = P1/P2, with MRS falling.
• Demand and Price Elasticity of Demand – Demand is the quantity of a good buyers are willing and able to buy at each price in a period. Market demand adds up all buyers' demand at each price. Demand depends on own price, income, prices of related goods, tastes, expectations and number of buyers. A change in own price moves us along the curve; a change in any other factor shifts it. Price elasticity of demand (Ed) = % change in quantity ÷ % change in price; it can also be judged from total expenditure.

6. Producer Behaviour and Supply

Production function · Cost and revenue · Producer's equilibrium and supply

• Production Function: TP, AP, MP and Returns to a Factor – A production function shows the maximum output a firm can get from given inputs: q = f(L, K). In the short run some inputs are fixed, so output changes only by changing the variable input. TP is total output, MP is the extra output from one more unit of the input, and AP is output per unit. As more labour works on fixed land, MP first rises, then falls, and finally becomes negative: the law of variable proportions (returns to a factor).
• Cost and Revenue: TC, AC, MC and TR, AR, MR – Cost is what a firm spends on inputs. Total cost (TC) = total fixed cost (TFC) + total variable cost (TVC). Dividing by output gives AFC, AVC and AC; marginal cost (MC) is the extra cost of one more unit. AFC keeps falling; AVC, AC and MC are U-shaped, and MC cuts AVC and AC at their minimum. Revenue is money from sales: TR = P × q, AR = TR/q = price, MR = extra TR from one more unit. With a fixed price AR = MR; with a falling price MR lies below AR and TR is highest where MR = 0.
• Producer's Equilibrium and Supply – A producer is in equilibrium when profit is the highest and there is no reason to change output. By the MR–MC approach two conditions must hold: MR = MC, and MC must be rising (MC cuts MR from below). Supply is the quantity firms are willing and able to sell at each price. Market supply adds all firms' supply. Supply depends on own price, input prices, technology, taxes, prices of other goods, number of firms and expectations. Own price moves us along the curve; other factors shift it. Es = % change in quantity supplied ÷ % change in price.

7. Forms of Market and Price Determination under Perfect Competition

Perfect competition and price determination · Simple applications

• Perfect Competition and Price Determination – In perfect competition, very many firms sell the same product to very many buyers, so each firm is a price taker. The market price is set where market demand equals market supply (Qd = Qs). If demand rises, price and quantity both rise; if supply rises, price falls and quantity rises.
• Price Ceiling and Price Floor – A price ceiling is a legal maximum price set below equilibrium; it causes a shortage (excess demand), queues, rationing and black markets. A price floor is a legal minimum price set above equilibrium; it causes a surplus (excess supply) that the government often buys and stores, as with Minimum Support Price. A ceiling above, or a floor below, equilibrium has no effect.

8. Project Work

Project in economics

Coming soon