Factors that influence PED

• The availability of substitutes - lots of substitutes then a product is likely to be elastic
• The necessity of the product - if a product is essential such as petrol then it is likely to be inelastic
• The brand loyalty people have to the product - the more loyal we are to a product, it is less likely to have elastic demand
• Time - if businesses change price, customers might spend time looking around for alternative products - so price changes might have less impact in the short term but become more elastic in the long term