ACCA Applied Skills · Performance Management
Pricing decisions: formula sheet
Key formulas
- Price elasticity of demand
- PED = % change in quantity demanded ÷ % change in price
- Use the absolute value. Above 1 is elastic, below 1 is inelastic, equal to 1 is unitary.
- Demand line
- P = a − bQ
- a is the price where demand is zero. It is the intercept on the price axis.
- Gradient b
- b = change in price ÷ change in quantity
- If price falls $1 for every 50 extra units, b = 1 ÷ 50 = 0.02.
- Finding a
- a = P + bQ
- Use any known price and quantity point on the line.
- Marginal revenue
- MR = a − 2bQ
- The slope is twice that of the demand line. It holds for a straight-line demand curve.
- Profit-maximising output
- MR = MC, so Q = (a − MC) ÷ 2b
- Substitute Q back into P = a − bQ to get the price. This assumes MC is constant.
- Point elasticity on a straight line
- PED = (1 ÷ b) × (P ÷ Q)
- Elasticity changes along the line. It is higher at higher prices.
- Revenue effect
- Elastic: raise price, revenue falls. Inelastic: raise price, revenue rises.
- Reverse the effect for a price cut.
- Demand function
- P = a − bQ
- P is price, Q is quantity demanded. This is a straight-line demand curve.
- Slope of demand curve (b)
- b = change in price ÷ change in quantity
- Use the price change for a given change in demand. For example, a $5 price change that moves demand by 500 units gives b = 5 ÷ 500 = 0.01.
- Intercept of demand curve (a)
- a = current price + (b × current quantity)
- This is the price at which demand would be zero. It is the same as the price at Q = 0.
- Marginal revenue function
- MR = a − 2bQ
- Same intercept as the demand function, twice the slope. Derived from total revenue PQ = aQ − bQ² by differentiating.
- Profit-maximising condition
- MR = MC
- MC is usually the constant variable cost per unit.
- Profit-maximising quantity
- Q = (a − MC) ÷ 2b
- Comes from solving a − 2bQ = MC.
- Profit-maximising price
- P = a − bQ
- Substitute the optimal Q into the demand function. Do not use the MR equation.
- Maximum profit
- Profit = (P − MC) × Q − fixed costs
- This holds where MC is the constant variable cost per unit.
- Full cost
- Full cost per unit = variable cost per unit + fixed overhead absorbed per unit
- Fixed overhead per unit = budgeted fixed overhead ÷ budgeted activity level.
- Price with mark-up on cost
- Selling price = cost × (1 + mark-up %)
- Use full cost for full cost-plus and variable cost for marginal cost-plus.
- Mark-up on cost
- Mark-up % = (selling price − cost) ÷ cost × 100
- Use this to find the mark-up a current price implies.
- Margin on selling price
- Margin % = (selling price − cost) ÷ selling price × 100
- Margin % = mark-up % ÷ (1 + mark-up %).
- Required mark-up for a target return
- Mark-up % = required profit ÷ total cost base × 100
- Used when a target profit is set and the cost base is known.
- Skimming: when it suits
- Inelastic demand at launch + unique or protected product + high development costs + short life cycle
- These are conditions, not a calculation. Check each against the scenario. Not all need to hold.
- Penetration: when it suits
- Elastic demand + economies of scale + easy entry for rivals + long life cycle or need for early share
- Again, these are indicators. Use the facts given and say which matter most.
- Price elasticity of demand
- PED = % change in quantity demanded ÷ % change in price
- Ignore the sign when comparing. PED above 1 is elastic, so a price cut raises revenue. PED below 1 is inelastic.
- Profit at a given price
- Profit = (Price − Variable cost per unit) × Volume − Fixed costs
- Use this to compare the two strategies over the period in the question.
- Conditions for price discrimination
- Separable markets + different price elasticities of demand
- Both are needed. Charge more in the less elastic (less price-sensitive) market.
- Bundle price test
- Bundle price < sum of individual prices, and bundle contribution > contribution lost from discounts
- Compare total contribution with and without the bundle, not just revenue.
- Loss leader test
- Contribution from extra sales of other products > loss on the leader
- The strategy only pays if customers buy the profitable items as well.
- Volume discount contribution
- Contribution per unit at discounted price × volume − contribution at normal price × volume
- Use contribution (selling price less variable cost) to judge if a discount increases profit.
- Minimum price of a special order
- Minimum price = Relevant cost of the order (incremental cash costs + opportunity costs)
- Any price above this increases profit. Add a margin if the question asks for a target profit.
- Relevant cost of materials
- Already held and no other use: scrap/resale value (₹0 if none). Held and used elsewhere: replacement cost. Not held: current purchase cost.
- Use the cost of the benefit given up. Check whether the material is regularly used.
- Relevant cost of labour
- Spare capacity: ₹0 extra if paid anyway. Fully used: pay + lost contribution (after pay) from the diverted work.
- Count labour once only. Pay plus contribution after pay equals contribution before labour cost. Use one of these routes, never both.
- Opportunity cost with scarce resource
- Opportunity cost = contribution per unit of resource × units of resource diverted
- Add this to the cash cost of the order. The opportunity cost is the contribution forgone. Count the cost of the resource once only: either add the resource cost to contribution calculated after it, or use contribution before it and add nothing more.
- Make-or-buy with no scarcity
- Make if relevant variable cost of making < buying price
- Include avoidable fixed costs. Ignore unavoidable fixed costs.
Quick revision
- Price elasticity of demand = % change in quantity demanded ÷ % change in price.
- If demand is elastic (absolute value above 1), a price cut raises revenue.
- If demand is inelastic (absolute value below 1), a price rise raises revenue.
- Profit is maximised where marginal revenue = marginal cost.
- With a straight-line demand curve P = a − bQ, MR = a − 2bQ.
- Find the quantity from MR = MC, then put it into the demand function to get the price.
- Full cost-plus: price = full cost per unit + mark-up.
- Cost-plus is simple but ignores demand and competitors.
- Market skimming: high initial price, then lower; suits novel products with less price-sensitive buyers.
- Market penetration: low initial price to win share quickly; suits price-sensitive markets and scale economies.
- Special order price should at least cover relevant costs, including any opportunity cost.
- Make-or-buy: compare the relevant cost of making with the buying price, and consider capacity and quality.
Common mistakes
- Working out the % change using the new figure as the base. Fix: Always divide the change by the original (starting) figure.
- Using b as the quantity change per $1 price change, instead of price change per unit. Fix: Invert it. b = $1 ÷ 50 units = 0.02. Check by seeing that P falls as Q rises.
- Using MR = a − bQ instead of a − 2bQ. Fix: Always write the demand equation first, then double the b term in MR. Keep a unchanged.
- Calculating b upside down, as quantity change ÷ price change. Fix: b is price per unit of quantity: price change ÷ quantity change. Check that b is a small number such as 0.01.
- Mixing up mark-up on cost with margin on selling price. Fix: Check the base. Mark-up uses cost: cost × (1 + m). Margin uses price: cost ÷ (1 − m).
- Using the wrong activity level to absorb fixed overhead. Fix: Use the activity level given for absorption, usually budgeted production, unless told otherwise.
- Reversing the two strategies, such as saying skimming means a low price. Fix: Remember that skimming takes the cream off the top, so the price is high. Penetration pushes into the market, so the price is low.
- Listing advantages and disadvantages without linking them to the scenario. Fix: Pick the points that match the case facts and quote them. Say which advantage applies and why.
- Confusing loss leader with captive product pricing. Fix: Ask whether the customer is locked in. Captive means the add-on only works with the main product. Loss leader just draws customers in.
- Saying price discrimination works whenever prices differ. Fix: Always state the two conditions: separable markets and different elasticities. Also note that the product must be the same, not a different version.
Exam tips
- Show the demand line, the MR line and the MR = MC step on separate lines. Marks are given for method even if the final number is wrong.
- In objective test questions, you only get marks for the right answer. Do a quick check: substitute your optimal Q back into the demand line.
- For written Section C parts, always tie the factor to the scenario (for example, many substitutes means elastic). Generic lists score poorly.
- Do not forget to state the elastic or inelastic conclusion and what it means for the pricing decision.
- When fixed costs appear in a question, say they are irrelevant to the optimal price, then ignore them.
- In Section C, show the demand equation, the MR equation and the MR = MC line separately. Marks are given for each step, even if the final figure is wrong.
- In objective test questions there are no part marks, so check b and a with the original data before you choose an answer. Plugging your Q back into the demand equation takes seconds.
- Read the cost data carefully. Use the variable cost per unit as MC, and bring in fixed costs only when asked for profit. Watch for MC that changes at a given volume, which you should state and test.