Economics Paper 2, WASSCE (SC), 2018

Question 7

 

(a) What is a demand schedule?
 (b) State the law of demand.
 (c) Using appropriate examples, explain the following types of demand:
  (i)         competitive demand;
  (ii)        derived demand;
  (iii)       joint demand;
   (iv)       composite demand.

  Observation

This question also attracted lotsof candidates, most of whom scored above average marks. Candidates were expected to define demand schedule, state the law of demand and explain using appropriate examples the types of demand  in the (a), (b) and (c) parts of the question respectively. The candidates that attempted this question were able to define demand schedule and state the law of demand but mixed up their explanation of the types of demand in the (c) part of the question, hence their performance was a bit above average.
The candidates were expected to answer thus:

 

(a) A demand schedule is a table which shows the different quantities of a commodity which consumers are willing to buy at various prices at a particular time.                                                           

                                                    

(b) The law of demand states that at a higher price, less is demanded and at a lower price,more is demanded, other things being equal.             

         

(c)(i)    Composite demand: This refers to the total or aggregate demand for a commodity which has several uses. The composite demand for cassava for instance comprises the demand for cassava for its various uses e.g. making garri, for making industrial starch, for making fufu, etc.

    (ii)    Derived demand: This is demand for a commodity which is not needed for direct satisfaction, but rather for the production of other goods e.g. the demand for labour and other factors of production.                                           

    (iii)   Joint or complementary demand: This refers to demand for commodities which are            needed together to satisfy a want. There is joint demand for two commodities when they are such that without one, the other cannot satisfy a want e.g. car and petrol, torch and            batteries etc.                                       

(iv)      Competitive demand: This applies to commodities which can be used interchangeably. Demand for substitute goods is thus competitive e.g. milo and bournvita, meat and fish, turkey and chicken etc.