Delayed Impact

State

class whynot.simulators.delayed_impact.State

State of the lending simulator.

credit_score = 700

Agent credit score

group = 0

Group membership (sensitive attribute) 0 or 1

loan_approved = 0

Whether the loan was approved on the last round.

profits = 0

Running total of the banks profit/loss for the agent

repaid = 0

Potential repayment (computed even for loan_approved=0) on last round

Config

class whynot.simulators.delayed_impact.Config

Parameters for the simulation dynamics.

credit_scorer()

Maps the true credit score to the reported score

default_score_change = -150

Applican’t score change after default

default_utility = -4.0

Bank default utility

delta_t = 1

Simulator step size (Unused)

end_time = 1

Simulation end step (in rounds)

min_score = 300

Minimum credit score

repayment_score_change = 75

Applicant’s score change after repayment

repayment_utility = 1.0

Bank repayment utility

start_time = 0

Simulation start step (in rounds)

threshold_g0 = 650

Lending threshold for group 0

threshold_g1 = 650

Lending threshold for group 1

Interventions

class whynot.simulators.delayed_impact.Intervention(time=100, **kwargs)

Parameterization of an intervention in the lending model.

Examples

>>> # Change the group 0 threshold to 700
>>> Intervention(time=0, threshold_g0=700)

__init__(time=100, **kwargs)

Specify an intervention in the dynamical system.

Parameters:

• time (int) – Time of the intervention (days)
• kwargs (dict) – Only valid keyword arguments are parameters of Config.

Experiments

Experiments for lending simulator.

whynot.simulators.delayed_impact.experiments.CreditBureauExperiment = CreditBureauExperiment

Effects of interventions on credit scoring on group score changes