Methods, apparatus, systems and articles of manufacture to identify local trade areas are disclosed. An example method includes selecting, with a processor, census block groups (CBGs) associated with a retailer location, identifying, with the processor, a plurality of stores within the selected CBGs and associated all commodities volume (ACV) values for respective ones of the plurality of stores, calculating, with the processor, similarity index values associated with respective pairs of the plurality of stores, generating, with the processor, local trade areas (LTAs) of subgroups of the plurality of stores based on a comparison of the similarity index values to a similarity threshold value, and when a respective one of the LTAs includes a violation of a releasability criterion, preventing, with the processor, erroneous disclosure of market share information by re-distributing the stores within the respective one of the LTAs to a geographically adjacent LTA.