What is one limitation commonly associated with consumer panel data?

Consumer panel data is a powerful tool for understanding consumer behavior, but one significant limitation is that it may not capture all consumer behaviors. This is because consumer panels typically consist of a selected group of individuals who voluntarily report their purchasing habits over time. While they provide insight into these participants' buying patterns, they might overlook behaviors that occur outside of regular shopping, such as impulse purchases that weren't planned, purchases made from other channels like online marketplaces, or consumers who choose not to participate in the panel.

Additionally, consumer panel data may be limited by the specific categories and brands included in the research, which can affect the representativeness of the data. If certain demographics or purchasing behaviors are underrepresented in the panel, the conclusions drawn from this data could lead to misinterpretations or incomplete understandings of broader market trends.

In contrast, the other options point to aspects of consumer panel data that, while potentially true, do not encapsulate the fundamental nature of the data's limitations regarding behavior capture. For example, concerns about geographical diversity or expense may be relevant in broader discussions about data collection methods, but they are not the primary limitation of consumer panel data per se.