If an economist is trying to predict the outcome from particular causes and effects, what is the best tool (s) for her to use in order to test out her economic model?

Answer: Mathematical functions

Explanation:

Many models use mathematical functions in order to investigate, theorize, and fit theories into economic situations. Economic models have two functions: to simplify and abstract from observed data, and also, to serve as a selection means for data based on a paradigm of econometric study.