Purpose of the Aggregation Risk Module
This module explains the risk introduced when residential data for Johannesburg is read primarily at the aggregated city level. Its purpose is to clarify how aggregation obscures submarket distinctions and alters visibility signals, leading to misinterpretation if citywide readings are treated as representative or exhaustive.
Aggregation as a Visibility Compression Mechanism
City-level aggregation compresses residential listings from multiple districts and submarkets into a single analytical layer. In doing so, it blends areas with distinct housing forms, publication practices, and participation levels. This compression changes the apparent distribution of residential visibility without changing the underlying structures that generate listings.
Dominance of High-Visibility Submarkets
Within aggregated views, submarkets with high publication frequency or centralized management tend to dominate observable patterns. Their repeated listing rotation can disproportionately influence citywide totals, while submarkets with low or irregular visibility recede. This dominance reflects circulation mechanics rather than residential prevalence.
Loss of Boundary-Specific Meaning
Submarket and district boundaries carry interpretive meaning by isolating areas with similar visibility mechanics. Aggregation dissolves these boundaries, removing the contextual information needed to understand why listings appear where they do. Once boundaries are removed, visibility signals lose their explanatory grounding.
Misinterpretation Risk at City Scale
When aggregated readings are treated as descriptive of the city as a whole, there is a risk of assuming uniform residential structure or activity. Such assumptions extend beyond what listing-based data can support. Aggregation therefore introduces a structural risk by encouraging interpretation without boundary control.
Interpretation Boundaries for Aggregated Views
Aggregated city-level views should be used only as orientation layers that indicate where listings circulate in broad terms. They cannot support conclusions about residential composition, scale, or distribution. This module establishes a boundary against extrapolating aggregated visibility into citywide residential claims.