Competition in Retailing. Market Definition. Product markets versus retailer markets : T he relevant product markets should be defined first, and then the relevant retailer market should be defined with respect to the type of retailer .
The former include regulatorybarriers to entry. For example, insome retail markets (such as pharmacies and bettingshops), there are regulations restricting the number of local competitors. Similarly, forsome retail products (such as contact lens solutions), there are regulations
restricting the types of retailers which can sell the product.
In the grocery sector, for example, those retailers which stock the most own-brand products(Sainsbury’s, Tesco and Asda) are also positioned more upmarket than those which focus on brandedproducts (Kwik Save, Aldi and Netto). The nature of this correlation is complex and causation works intwo directions: