Where does filtering usually occur in urban areas?

Filtering typically refers to the process through which housing units transition from being occupied by higher-income residents to being occupied by lower-income ones, often as neighborhoods age and housing stock changes. This process is most commonly observed in large metropolitan areas where there is a dynamic market, including active construction.

In bustling urban settings, market conditions drive the availability of a diverse range of housing types and costs. As new constructions arise, older structures may become more affordable, leading to a change in the socioeconomic demographic of residents over time. This is a characteristic feature of larger cities where the influx of new developments can lead to gentrification in other neighborhoods, which may result in filtering in surrounding areas.

In contrast, filtering is less likely to occur in suburban areas where population density is low, as these areas may not experience the same rate of housing turnover or demand fluctuations. Similarly, rural regions with minimal development often lack the economic diversity necessary for such changes to manifest. Towns experiencing population decline might see stagnant or decreasing demand for housing, making filtering less relevant in those contexts. Thus, the correct answer highlights the active and ongoing changes in housing markets typical of large metropolitan areas.