The literature suggests several reasons NORCs develop. According to Hunt, NORCs evolve in three ways--"aged-left-behind," "aging in place," and "in-migration."20 The first two types of NORCs are similar in that both are populated chiefly by long-term residents--the first by residents who stayed in a community characterized by out-migration; the second by older residents who gradually became the dominant population in a stable community. The third type is distinguished by the proportion of older residents who are new to the community. In other articles, Hunt refers to this last type of NORC as "retirement destination."21
Marshall and Hunt focused on NORCs in rural areas and came up with different reasons.22 They used census data to classify rural NORCs by the factors that attract or retain older residents. Amenity NORCs attract younger, healthier, and more active retirees who typically move to escape urban lifestyles. Convenience NORCs often attract people from a nearby rural area, usually the older elderly, looking for greater availability of services and social opportunities. Bi-focal NORCs attract retirees seeking natural amenities who also want to be close to family and friends. Hunt also applied these distinctions in non-rural settings, noting that residents of the different types of NORCs generally have different characteristics, including age, health status, and income.23
Hunt describes many different circumstances that may lead to each type of NORCs. He considers the economic, social, and environmental conditions that affect the community itself and the options open to residents, both older and younger, given their available resources and abilities. According to Hunt, an aged-left-behind NORC may develop, for example, when an area has a significant economic decline. This type of community might be found in "rust-belt" areas where manufacturing jobs have declined. While younger residents may leave to find better economic opportunities, many older residents stay either because of emotional or economic ties to the area or lack of financial resources.
In contrast, an aging-in-place NORC typically has residents with a strong desire to remain in their communities and maintain ties to their social networks, which may include children and grandchildren, friends and neighbors, health providers, places of worship, and local businesses. Hunt notes that these communities may have residents with varying incomes.24 Some urban neighborhoods might be examples of this type of NORC, where the younger generation may have moved to the suburbs leaving the older generation in the family homes.
In-migration NORCs may develop when older people move to an area for the convenience or attractiveness of the community. For example, in-migrants may seek the companionship of others their age, proximity to shopping and services, a hospitable climate, availability of numerous activities, and a more leisurely life. These NORCs may be found in vacation or resort areas and may have first attracted seniors seasonally.
Hunt's research on apartment-based NORCs provides an example of the development of another type of NORC, which he calls an apartment-complex type.25 From his description, these NORCs appear to be a variant of the in-migration NORC. Hunt interviewed residents in three Madison, Wisconsin, apartment communities to learn what attracted older residents to the community. He found that older people often decided to move when the size and maintenance requirements of their homes became problematic--owing to the death of a spouse or the resident's poor health, for example. Residents reported that, once they decided to move, three main factors affected their choice of where to move. Location was identified as the chief initial attraction; residents often chose the site to be close to family or friends, shopping, and services. Management, particularly building maintenance, influenced the attractiveness of the apartment-complex, based on word of mouth and testimonials from residents. Finally, the design of the building can help eliminate potential barriers to independent living.
NORCs are not static; residents of all ages move in or out, resulting in an evolving demographic profile. In his study of apartment-complex type NORCs, Hunt examined the reasons older people leave the community.26 When asked if they planned to move, about 30 percent of the NORC residents in Hunt's survey said "maybe" and another 10 percent said "yes". Most respondents cited a need for more health care or lower rental costs. The importance of housing costs was confirmed in another survey of older people conducted in 2003 that found that 93 percent of older people surveyed wanted to remain in their homes for as long as possible but, of these, over a third were concerned about affordability.27 In Hunt's apartment-complex study, physical environment also played a role. Those who left the NORC reported they had left because of such barriers as stairs in the living unit or to the laundry room.28
Subject matter experts agreed that two major trends affect the evolution of NORCs--aging in place and migration of older people--and that people remain in their communities as they age or move into new communities for the reasons that Hunt noted in Wisconsin. Factors affecting migration include the community's affordability, accessibility, amenities, and proximity to family and friends. The experts speculated that there might also be a cultural component, based on such factors as religious, ethnic, or socioeconomic homogeneity.
The experts further agreed that the proportion of a community's population made up of older people could increase or decrease over time, so the community composition could change. Some communities can lose older people often for the same reasons that had originally attracted them, such as the changing affordability of housing or a change in building management that affects how management responds to the needs of older people. Some experts noted that NORCs might remain stable, sustaining themselves through in-migration, and cited the New York City NORCs as an example.