Who Reports Withdrawal Dates in the Western Interconnection Queue, and Does It Matter?

Berkeley Lab's Queued Up publishes a median duration from interconnection request to withdrawal for the non-ISO West. That figure is computed from the 12.1% of western withdrawals that carry a recorded withdrawal date, filed with five or six of the region's thirty-one transmission providers. This analysis tests whether that reporting subset is representative of the region it is used to describe. It is not: technology mix, queue cohort and interconnection service type all differ from the regional population at p < 1e-10, while project capacity does not. But standardising the subset to the region's actual composition moves the median by less than three months, with an interval including zero and a sign that reverses under a truncation-matched observation window. A validation exercise inside the well-covered ISO regions shows why: technology, cohort and capacity together explain under 5% of the variance in withdrawal duration, so a composition gap of this size has little room to move a median. A companion logistic regression over the 7,991 western requests with complete predictors, which requires no dates, finds solar the most withdrawal-prone technology, larger projects more likely to be withdrawn, and roughly a quarter of the latent variation in withdrawal risk sitting between providers rather than between projects. Includes the full R analysis pipeline, result tables and figures.