Which of the following is NOT a factor determining supply?

Step 1: Analyze the question We are asked to find the option that is NOT a determinant of supply. Supply is the quantity of a good that producers are willing and able to offer for sale at various prices.

Step 2: Recall the determinants of supply The main factors that affect supply (apart from the good's own price) are:

• Cost of production (wages, rent, raw material prices). Higher costs reduce supply.
• Technology. Better technology lowers costs and raises supply.
• Number of producers/firms. More firms mean greater market supply.
• Weather/climatic conditions. These matter especially for agricultural goods.
• Prices of related goods, taxes and subsidies, and government policy.
• Producers' expectations about future prices.

Step 3: Test each option

• A. Cost of production: a determinant of supply.
• B. Climatic condition or weather: a determinant, especially for farm produce such as cocoa, yam and rice.
• C. Income of the producers: not a standard determinant. Income of consumers affects demand, not supply. Producers' supply decisions depend on costs, prices and profit expectations, not on the producers' personal income.
• D. Number of producers: a determinant, since market supply is the sum of all sellers' supply.
• E. Technological development: a determinant, since it changes production efficiency and cost.

Step 4: Conclusion The only option that is not a recognized determinant of supply is income of the producers.

Exam tip: Remember the split: income of consumers, tastes, and prices of substitutes are mainly demand factors, while costs, technology, number of firms, weather and taxes/subsidies are supply factors. If an option mentions "income," ask yourself whose income it is. Consumer income points to demand.