LendingClub consumer loans · loans · 2007–2015

Which loans should a lender approve?

A credit decisioning engine that decides approve or decline, then measures what that decision does to profit, losses, and fairness. The model learned from 2007–2013, every cutoff was chosen on 2014, and every result below is on 2015 loans it never saw, using what each borrower actually repaid.

more profit than approving everyone, from declining the riskiest (4% cost of funds)
more profit than ranking applicants by LendingClub’s own grade, at the same approval rate
ROC-AUC on the 2015 test set, vs for LendingClub’s grade alone

What the data says

    Approval strategy

    Rank applicants by
    Total net profit on 2015 loans by approval rate
    PolicyApprovedDefault rateDollar lossProfitvs approve all

    The chosen policy is the approval rate that maximized 2014 profit, applied unchanged to 2015. The hindsight row is a yardstick: it uses 2015 outcomes, so no lender could have picked it.

    What this means

    Vintage curves

    Share of each year’s 36-month loans charged off, by months since issue. Dashed lines are vintages that hadn’t finished when the data ends.

    What this means

    Applicant explorer

    Every decision comes with a probability of default and three plain-English reasons.

      Application

      Declines are over-sampled for illustration. The chosen policy declines about of applicants. 300 real 2015 applicants: 250 spread evenly across the risk range, plus 50 from above the cutoff. Reasons are the features that raised this applicant’s risk most (SHAP values). LendingClub’s own grade and rate are never given as reasons.

      Fairness

      Operating point
      Approval rate relative to the best income band (1.00 = same rate). Below 0.80 fails the four-fifths screen.
      Among approved applicants: default rate the model predicted vs what actually happened, by income band

      What this means

      Limitation. The data has no protected attributes (race, sex, age), and none were inferred. Income, home ownership and state are not protected classes. The four-fifths screen is a first check for groups that may overlap with protected classes. It is not a finding of discrimination, and it doesn’t replace a proper fair-lending review.

      Monitoring

      Population stability index vs 2007–2013 training loans, model score and top features. Above 0.10 is a moderate shift; above 0.25 a major one.

      What this means

      Method & limitations

      Built to avoid the two classic traps in credit data: leakage and survivorship bias.

      Data

      Validation

      Split by time, not at random: train on 2007–2013, choose every setting and cutoff on 2014, report once on 2015. Model inputs are application-time fields only. Automated tests keep outcome columns and geography out of every model, and LendingClub’s price out of the borrower-only model.

      Models

      Profit

      Net profit = total payments received (including recoveries) − collection fees − funded amount, from actual outcomes. Cost of funds = rate × average outstanding balance × years outstanding. The rate is an assumption.

      Limitations