Postal codes are one of the most common data points that researchers and analysts turn to to get a more nuanced sense of trends in more narrowly defined geographic areas. However, re-purposing this data to do so can be an excellent example of the power and limitations of administrative data. Although we can certainly get a far more nuanced look at information beyond the municipality level by using postal codes, it’s also important to note that they were designed to facilitate mail delivery routes rather than demographic or socioeconomic analysis. As a result, areas defined by postal codes can range greatly by size and can often be misaligned with commonly perceived neighbourhood boundaries.
For a more thorough look at the limitations of postal codes, some potential alternatives, and even some source code if you’re looking to conduct your own analysis, check out this article. Please note that this was published by an American writer, but that the parallels between ZIP/postal code analysis still ring true here.