Wednesday, February 22, 2017

A location model based on rent

I have developed a location model based on rent. In this model, the rent of each cell is calculated by taking the average of agents' income in this area. Agents have different income levels and requirements on space. Agents want to be located in the most accessible area they can afford where their preferences for space are matched.

There are two types of agents: residents and employers. Residents have high income (e.g. financial services), middle income (e.g. teachers and other professional occupations) and low income workers, which are classed as ‘commerce’, ‘service’ and ‘industry’ respectively. These classes are additionally broken down by age as young (18-34), middle aged (35-65) and old (66+). The agent’s age is calculated randomly when it is first created (18-67). Each agent desires a certain amount of space which is broken down by age categories.

Employer agents were designed to reflect the residential agents’ employers, and subsequently the same three groups of ‘commerce’, ‘service’ and ‘industrial’ were used to represent employers’ different roles instead of age, they have a tenure set between 0-6. employer agents’ decrease their tenure to zero. Once zero is reached, the employer can move. As with residents, employers have a space requirement. For example industrial firms are driven by the need for large amounts of land while financial services (i.e. ‘commerce’ employer) need less land but want a more central location. Each employer also has an income which is four times that of residents.

It is assumed that younger residential agents will move more frequently (every 2 iterations on average) than those who are middle aged (every 5 iterations) with the older residents moving the least (every 10 iterations, On the other hand, employers only move if their tenure is 0. Once an employer agent has moved and finds a suitable location, its tenure is reset to 6 and cannot move for 6 iterations of the model.

Agents of either residential or employer type wanting to be located in the most accessible area they can afford where their preferences for space are matched. An alternative zonal system is used, based on a series of small overlapping areas which allow agents to search the entire area which is not restricted to such boundaries and allows agents to identify clusters spread across such boundaries.

When an agent decides to move, it goes through the list of areas and finds which area is the most attractrive area (in this area its based on accessability). The agent initially moves to the centre of the area, then searches the area for an affordable neighborhood.

The results with one city center:


The results with new city center:

The code can be found here: https://github.com/YangZhouCSS/Bitrent