Shivam Ashokbhai Lalakiya

Auxiliary-table timing, not splitter choice, dominates leakage in donor propensity models: evidence from synthetic and real fundraising panels

Donor-propensity models built from CRM exports routinely join in auxiliary tables — clinical encounters, event attendance, wealth-screening appends — that arrive as a separate table passed to a transformer's constructor rather than as rows of X. Because those rows are never part of any train/test split, standard leakag...