Beginning with the March 8, 2017 Productivity and Costs news release, BLS will implement improved methodology for calculating hours-worked to hours-paid ratios. Currently, BLS uses the National Compensation Survey (NCS) hours-worked to hours-paid ratios for NAICS 3-digit industries from 2001 forward only as a reference series to carry forward levels of ratios provided by the discontinued BLS Hours at Work Survey. The new methodology will take advantage of the more detailed NCS ratios by making them the basis for ratio levels and applying them at the 3-digit industry level back to 1996. From 1990 to 1995, ratios will be estimated using data from the BLS Hours at Work Survey and adjusted to be consistent with the ratios from NCS. BLS will continue using ratios provided by the BLS Hours at Work Survey for years prior to 1990. NCS ratios will be incorporated on an annual basis and estimated for intermediate quarters.