In this blog post, we'll explore what diffusion of innovation means in geography.

Diffusion of innovation is the process by which culture, technology, or ideas from one region or social group spread to other regions or social groups over time. Geography recognizes that the diffusion of innovation is a spatial and temporal process, and describes the spatial diffusion process over time in three stages: generator, diffuser, and deep saturation. During the generator phase, innovations are adopted in regions close to the source of the innovation, while innovations are not adopted in regions farther away, resulting in large regional disparities in innovation adoption rates. During the diffusion phase, the innovation spreads from the initial receptive region to distant regions. In the deepening, saturation phase, innovation diffusion occurs across all regions, regardless of distance from the original source, and regional disparities in adoption rates gradually disappear.

The spatial diffusion of an innovation is described by contagion and hierarchical diffusion. Contagious diffusion is characterized by the neighborhood effect, which states that the closer the distance between an innovation source and potential adopters, the faster the innovation spreads. The closer the distance between the source and the adopter, the more opportunities for face-to-face contact there are, so the diffusion of an innovation is primarily driven by personal communication rather than mass media. On the other hand, hierarchical diffusion is characterized by the hierarchy effect, where the larger the city, the better the diffusion of innovation. Hierarchical diffusion allows innovations to spread from larger cities to smaller ones. However, in the real world, both contagion and hierarchical diffusion can occur simultaneously. For example, an innovation that originates in a large city may spread to a large city far away, while simultaneously spreading to the small and medium-sized cities surrounding the large city.

The number of adopters of an innovation changes over time. Initially, the number of adopters grows slowly, but at some point it starts to grow rapidly and eventually saturates. This is because individual adopters differ in the timing of their adoption. Innovation adopters are divided into four groups based on the chronological order in which they adopt an innovation: a small number of innovators, who are the first to adopt an innovation; a large number of early adopters, who adopt an innovation after a period of deliberation; a large number of late adopters, who adopt an innovation after seeing others adopt it; and a small number of latecomers, who are reluctant to try new things and adopt an innovation long after the fact.