Objectives

If adaptive traits explicitly act to increase some measure of the individual's success at meeting some objective, what exactly is that the objective and how is it measured?

This concept applies to adaptive behaviors that use direct objective-seeking; it defines the objective measure used to evaluate decision alternatives. (In economics, the term “utility function” is often used for an objective measure; in ecology, the term “fitness measure” is used.) If adaptive behaviors are modeled as explicitly acting to increase some measure of the individual’s success at meeting some objective, what is that measure, what does it represent, and how is it calculated? Objective measures are typically estimates of future success that depend on the decision being modeled; they can be thought of as the agent’s internal model of how its objectives will be met by the alternative being considered. Note that agents that are part of a Collective (defined below) or larger system—members of a team, social insects, leaves of a plant, cells in a tissue—can be modeled as having objectives that serve not themselves but the larger system they belong to. Describe, for each adaptive behavior modeled as direct objective-seeking: • What the objective measure represents: what characteristic of agent success does it model? An example from economics is expected wealth at some future time; in an ecological model an organism might use the probability of surviving until a future time or the expected number of future offspring. • What variables of the agent and its environment drive the objective measure. • How the measure is calculated. If it is a simple equation or algorithm, it can be described completely here; otherwise, provide a cross-reference to the submodel in Element 7 that describes it completely. Keep in mind that some other design concepts (e.g., Prediction, Sensing) may also describe parts of the objective measure. • The rationale behind the objective measure: why does it include the variables and processes it does?

In the immigrant model, 

The primary objective of each immigrant agent in the model is to find a suitable residential area to settle in based on specific criteria that maximize their well-being and meet their needs. These criteria are prioritized differently for each agent based on their individual characteristics and circumstances, such as:

1. Finding a residential area that offers cultural and social compatibility.
2. Ensuring economic similarity and stability.
3. Accessing convenient transportation options.
4. Providing educational opportunities for children if applicable.
5. The objective measure used by model households to decide whether to move is the percentage of adjacent households that have the same color as the household making the decision. “Adjacent” households are any households on the eight surrounding patches.
6. Investors rate business alternatives by an objective measure (utility measure, in economics) that represents their expected future wealth at the end of a time horizon (T, a number of future years) if they buy and operate the business. This expected future wealth is a function of the investor’s current wealth and the profit and failure risk offered by the patch: U = (W + TP) (1 – F)T where U is the expected utility for the patch, W is the investor’s current wealth, P is the annual profit of the patch, and F is the probability per year of the business failing. The term (W + TP) estimates investor wealth at the end of the time horizon if no failures occur. The term (1 – F)T is the probability of not having a failure over the time horizon; it reduces utility more as failure risk increases. (Economists might expect to use a utility measure such as present value that includes a discount rate to reduce the value of future profit. We ignore discounting to keep this model simple.)