The data below give estimates of the elasticity of demand for selected foods in the UK.

Income elasticity of demand

All foods0, 10

Beef0, 26

Margarine- 0, 22

Fresh potatoes- 0, 43

Fruit juices0, 95

Bread- 0, 18

Price elasticity of demand

Beef- 1, 24

Bread- 0, 25

Fresh potatoes- 0, 14

Fruit juices- 0, 65

Bread- 0, 37

Cross elasticity of demand for beef and pork:

Beef with respect to the price of pork0, 10

Pork with respect to the price of beef0, 25

a) With reference to the data, explain why

(i) All the price elasticities of demand are negative

(ii) Some income elasticities of demand are positive and some are negative

(iii) Beef has a high price elasticity of demand but a relatively low income elasticity of demand.

b) (i)Explain what is meant by the term "cross elasticity of demand'.

(ii)Comment on the values shown in the table for the cross elasticity of demand for beef and pork.

c) It is expected that levels of income in the UK will rise. It is likely that large food retailers will wish to take account of the data on elasticities in their marketing decisions.

(i) Explain with examples what uses might be made of the data by large food retailers.

(ii) Comment on the likely limitations of the data for their purposes.