Umm..im aware that hours billed is different from hours worked. If you go to nalp it shows both. According to nalp you work 2300 hours tops and make 160,000 at the big firms. That's less than 50 hours a week. That hardly seems like the long/hard hours everyone says big law requires.
And what incentive is there to really be honest about this on NALP? Depending on what the firm billable hour requirement is, the associate that only WORKS 2300 is likely NOT going to meet their bonus requirements, especially the first year where the learning curve is huge, and it takes twice as long to do a lot of tasks. Also, billing isn't steady. You're not going to work neat little 10 hour days every day; you're going to do the work that's given, which means you'll have slow weeks and slamming weeks.
Finally, there's a good pdf/handout floating around that shows how billable translate into real life work: extranet.law.unlv.edu/pdf/BillableHoursHandout.pdf
A quote from the pdf:
"So, while you’re in the office 10 hours a day, you’re billing for only 7.5 hours. If you work Monday through Friday, you’ll “work” 50 hours and have billed 37.5. If you do this all year long and take 5 weeks of off for vacation, holidays and sick days, you’ll work 47 weeks and bill 1762 for the year. To reach an 1800 billable requirement, you’ll need to pick up an additional 38 hours during the year by taking shorter lunch hours, coming in over the weekend, working longer days or taking less than five weeks of vacation. This exercise does not factor in your commute, non-billable training, pro bono work, serving on a Bar committee, writing an article for the bar journal, interviewing an applicant, etc."
A couple of points on this: An 1800 billable requirement seems low - you're looking at doing far more work on the weekends if you have to bill any more than 1800. This again assumes you're going to have 37.5 hours of billable work EVERY week. You may not. You may have some weeks where you're billing only 15 or 20 hours. That's even more hours to make up later (assuming you get the work later), and that's going to translate into 80 hour weeks here and there.
So I think I'd take a bet that if you have a Monday am call back, at least a couple of the associates did some work over the weekend.