price elasticity of supply can be influenced by the following factors except?

Analyze the question: We are asked which option does NOT influence price elasticity of supply (PES). Note that this is about supply (producers), not demand (consumers).

Explain the concept: Price elasticity of supply measures how responsive quantity supplied is to a change in price:

PES = % change in quantity supplied ÷ % change in price

The main factors that influence it are:

1. Time period: In the short run, producers cannot easily change output, so supply is inelastic. In the long run, supply is more elastic.
2. Cost of production: If costs rise sharply as output increases, supply is less elastic.
3. Nature of the product: Perishable goods and agricultural products (e.g., tomatoes, yam) are harder to adjust quickly, so supply is inelastic. Manufactured goods are easier to adjust.
4. Others: availability of raw materials, spare capacity, ease of storage, mobility of factors of production, and technology.

Go through the options:

• A. Time period: Influences PES. ✔
• B. Cost of production: Influences PES. ✔
• C. Size of consumer income: This is a determinant of demand (and income elasticity of demand), not supply. It is the exception. ✘
• D. Nature of the product: Influences PES. ✔

Answer: Option C is the factor that does not influence price elasticity of supply.

Exam tip: When you see "elasticity of supply," think of producers: time, costs, storage, perishability, inputs, and spare capacity. When you see words like consumer, income, or tastes, they point to demand. That is how you can quickly spot the odd one out.