In some markets, Uber’s efforts to recruit Lyft drivers are reportedly costing Lyft drivers up to half their hourly wages. In others it’s a little less, but still impactful financially: 12-24 percent depending on the area.

The numbers come from a New York Times report about Uber’s recruitment program SLOG. NYT’s Nick Bilton asked Lyft whether it had any way of tracking SLOG’s financial impact. Turns out, Lyft did.

Drivers can report an Uber recruiter when one jumps in their vehicle via a “feedback” section on the Lyft driver app. Because Uber recruiters take shorter trips than regular riders and they frequently order and cancel Lyft rides when it’s a driver they’ve been paired with before, recruiters hurt Lyft drivers’ profits.

SLOG was exposed earlier this week when The Verge did a huge report on the practice after interviewing Uber contractors who recruit Lyft drivers. SLOG appears to be a national program, in ten cities from Miami to…