Demand Analysis: Demand Concepts, Determinants, Law of Demand and Demand Forecasting Basics

For any business, demand is the starting point of planning. If a firm overestimates demand, it may produce excess stock and face losses. If it underestimates demand, it may lose sales and market share. Therefore, demand analysis helps a firm understand what customers want, what affects demand, and how demand may change in the future.

This chapter is frequently asked in exams as:

• Define demand and explain determinants of demand.
• Explain the law of demand with assumptions and exceptions.
• Distinguish between movement along a demand curve and shift in demand.
• Meaning and methods of demand forecasting.

Meaning of demand

In economics, demand is not just desire. Demand means:

1. desire for a product, and
2. ability to pay (purchasing power), and
3. willingness to pay at a given price, and
4. demand is always related to a specific time period.

So, demand can be defined as:

• “The quantity of a good that consumers are willing and able to buy at a given price during a given time period.”

Demand vs desire vs need

This distinction is useful for marketing and pricing decisions.

Demand function

A demand function shows the relationship between demand and factors affecting it.

General form:

• $Q_d = f(P, Y, P_r, T, A, N, E, \dots)$

Where:

• $P$ = price of the product
• $Y$ = income
• $P_r$ = price of related goods (substitutes/complements)
• $T$ = tastes and preferences
• $A$ = advertising and promotion
• $N$ = number of consumers
• $E$ = expectations (future prices/income)

Types of demand (brief)

Common types used in business:

• Individual demand and market demand
• Direct demand (consumer goods) and derived demand (inputs like steel)
• Joint/complementary demand (car and petrol)
• Competitive/substitute demand (tea and coffee)

Determinants of demand (factors)

Major determinants:

• Price of the product (P): usually, higher price → lower demand.
• Income of consumers (Y):
  • normal goods: income ↑ → demand ↑
  • inferior goods: income ↑ → demand ↓
• Prices of related goods:
  • substitutes: price of substitute ↑ → demand for our product ↑
  • complements: price of complement ↑ → demand for our product ↓
• Tastes, fashion, preferences: trend changes demand quickly.
• Advertising and sales promotion: effective ads can increase demand.
• Population / number of consumers: more buyers → more demand.
• Expectations:
  • expected future price ↑ → present demand may increase (stocking).
• Season and climate: umbrellas in rainy season, AC in summer.
• Availability of credit: easy EMI can increase demand for durable goods.

Law of demand (statement and explanation)

Statement

“Other things remaining the same, the quantity demanded of a commodity varies inversely with its price.”

Meaning:

• Price ↑ → Quantity demanded ↓
• Price ↓ → Quantity demanded ↑

Why does it happen? (simple reasons)

• Law of diminishing marginal utility: each extra unit gives less satisfaction; consumers buy more only at lower price.
• Income effect: price fall increases purchasing power, so consumers can buy more.
• Substitution effect: when price falls, the good becomes relatively cheaper than substitutes, so people switch to it.

Assumptions of law of demand

The law holds under these assumptions:

• income remains constant
• tastes and preferences do not change
• prices of related goods remain constant
• no expectation of immediate future price change
• quality of the product remains the same
• consumers behave rationally

These assumptions help isolate the price–demand relationship.

Exceptions to the law of demand

In some cases, price and demand may move in the same direction:

• Giffen goods: very inferior goods where income effect dominates substitution effect (rare).
• Veblen goods / prestige goods: higher price signals status (luxury brands).
• Speculation/expectations: expected future price rise increases current demand even at higher price.
• Necessaries: demand may not fall much with price increase (very inelastic).
• Quality perception: higher price is seen as higher quality for some goods.

Note: in exams, write that exceptions are special cases and the law is generally true.

Movement along demand curve vs shift in demand

This is a very common exam point.

Movement along the same demand curve (change in quantity demanded)

Happens due to change in price only.

• price falls → extension of demand
• price rises → contraction of demand

Shift of demand curve (change in demand)

Happens due to factors other than price (income, tastes, prices of related goods, etc.).

• demand increases → curve shifts right
• demand decreases → curve shifts left

Elasticity (quick link to next chapter)

Elasticity tells how sensitive demand is to changes in:

• price (price elasticity)
• income (income elasticity)
• other goods’ price (cross elasticity)

It is important for pricing, revenue planning, and tax impact analysis.

Demand forecasting: meaning and objectives

Demand forecasting means estimating future demand for a product in a given period.

Objectives:

• plan production and capacity
• manage inventory (avoid stockout and overstock)
• plan purchasing and supply chain
• plan manpower and budgeting
• support pricing and marketing decisions

Methods of demand forecasting (basics)

1) Survey methods (consumer based)

• consumer surveys/interviews
• market experiments/test marketing

2) Statistical methods (data based)

• trend projection (time series)
• moving average (simple smoothing)
• regression analysis (demand vs factors)

3) Expert opinion methods

• Delphi method (panel of experts, iterative)
• sales force composite (sales team estimates)

Choice depends on product type, data availability, time and cost.

Steps in demand forecasting (simple)

1. Define objective and time horizon.
2. Identify product and market segment.
3. Collect data (past sales, market conditions).
4. Select a forecasting method.
5. Prepare forecast and check reasonableness.
6. Monitor actual sales and revise forecast.

Mini tables & flowcharts for exam answers

Table 1: Determinants of demand (quick)

Table 2: Change in quantity demanded vs change in demand

Flowchart: Demand forecasting use

Forecast demand → Plan production/capacity → Plan inventory & purchasing → Budget & manpower → Improve sales & profit

Quick Recap (1-minute revision)

• Demand = desire + ability + willingness (for a time period).
• Determinants: price, income, related goods, taste, ads, population, expectations, season.
• Law of demand: price ↑ → demand ↓ (ceteris paribus).
• Exceptions: Giffen, Veblen, speculation, quality perception.
• Forecasting: estimating future demand for planning and control.