What does a higher Gini coefficient indicate about a model?

A higher Gini coefficient indicates better separation of outcomes for a predictive model. The Gini coefficient is a measure of statistical dispersion that quantifies the inequality among values of a frequency distribution, in this case, the predicted probabilities of different outcomes.

When it comes to model performance, a higher Gini coefficient reflects a greater ability of the model to distinguish between different classes, such as the positive and negative outcomes in binary classification tasks. Essentially, it means that the model can effectively rank the instances in a way that those with higher probabilities of the positive class are placed higher than those with lower probabilities.

This is valuable in contexts like credit scoring or risk assessment, where the goal is to accurately identify high-risk versus low-risk individuals. In such scenarios, a model with a higher Gini coefficient would lead to better targeting of resources and actions based on its predictions, thereby yielding more effective decision-making.

Other options, such as increased complexity, higher misclassification rate, or lower accuracy, do not directly relate to improving a model's ability to separate outcomes. In fact, a higher Gini coefficient is generally associated with improved model performance rather than complexity or misclassification issues, emphasizing its direct correlation with the effectiveness of the model in differentiating between the outcomes.