The SHRM/Rutgers LINE® data are collected through a survey of human resource professionals.  Data are collected from two samples of HR professionals at manufacturing firms and service sector firms. Because the manufacturing sector is more cyclically sensitive than nonmanufacturing, changes in this sector are often leading indicators of change in the overall economy. Compared with overall employment, employment in the manufacturing sector tends to decline sooner during periods of economic contraction and increase sooner during periods of economic expansion. The service sector is widely viewed as an area where future job growth will occur and is monitored closely for that reason.

Two parallel LINE® indices are released each month, one for manufacturing and one for the service sector. Each sample includes firms classified by their North American Industry Classification System (NAICS). Responses to the survey are weighted by BLS estimates of the percentage of the employment in each subsector.

LINE® data are not seasonally adjusted. We do not have a long enough series of monthly data points to permit us to calculate seasonal adjustment factors. The BLS does publish seasonal adjustment factors for its manufacturing employment series, and users are encouraged to be aware of these factors when interpreting the monthly indexes.

Users of the data should also be aware that many different factors, some of which may be unrelated to any true trend in manufacturing employment, could produce fluctuations in the composite index or its components. LINE® data reflects the experience of a sample of manufacturing firms. Users of this indicator should be very cautious when drawing conclusions about other industries and the overall employment outlook. Users are encouraged to consider LINE® data within the context of other available economic indicators.