Methodology
2000 - 2012 Methodology -- 2013 Methodology
The Bureau of Labor Statistics’ (BLS) Occupational Employment Statistics (OES) program in North Carolina conducts a semi-annual mail survey of employers to produce estimates of occupational employment and wages. This program collects data on wage and salary workers in non-farm civilian establishments, gathering employment and wage information on approximately 800 occupations within statewide industries, and reports the resultant occupational estimates by geographic area and by industry. In this study, estimates based on geographic areas are available at the state, metropolitan statistical area (MSA), county, workforce development board area and economic development region levels. The industry classification corresponds to the 2012 four-digit North American Industry Classification System (NAICS). The BLS produces occupational employment and wage estimates at the National level, which are available online at http://www.bls.gov/oes/current/oes_nat.htm.
The OES survey has been designed to produce estimates using three years of sample data. With approximately 12,000 establishments surveyed each year in North Carolina, a total of 36,000 establishments would be surveyed over a three-year period. Adjustments are applied to previous years’ wage data before combining with current data. For 2004 through 2006 semi-annual release dates, the most recent data set included in the release is approximately one year earlier then the release. For the annual releases beginning in 2007, the most recent data set is from May of the preceding year. The 2001 through 2003 releases were based on an annual survey spread over several months in the fourth quarter of the year. The year date for the survey period is two years earlier than the release date.
Employment is defined as the number of full-time and part-time employees, workers on paid vacation or other type of paid leave, workers assigned temporarily to other units and paid owners, officers and staff of incorporated firms. The survey excludes proprietors, owners and partners of unincorporated firms, unpaid family workers, workers on unpaid leave and contractors and temporary agency employees not on the company payroll.
Wages for the survey are straight time, gross pay, exclusive of premium pay. Base rate, cost-of-living allowances, tips, guaranteed pay, hazardous-duty pay, incentive pay, commissions, production bonuses and on-call pay are included. Excluded is back pay, jury duty pay, overtime pay, severance pay, shift differentials, non-production bonuses and tuition reimbursements.
There is a small group of occupations, primarily in teaching, where a standard work-year assumption is not considered valid. For this group, the annual wage is calculated directly from the reported data. An hourly wage for these workers cannot be calculated because the number of hours worked is not known. In addition to teachers, the occupations include actors, athletes, coaches, sports officials, flight attendants and pilots.
Hourly earnings data are collected in 12 wage intervals. Employers report the number of employees in an occupation by these intervals. With the exception of the upper open-ended wage interval, a mean wage value is calculated for each wage interval based on occupational wage data collected by the Office of Compensation and Working Conditions. The mean wage value for the upper open-ended wage interval is its lower bound. These interval mean wage values are then attributed to all workers reported in the interval. For each occupation, total weighted wages in each interval are summed across all intervals and divided by the total occupational employment. This calculates an estimated average (mean) wage.
The Bureau of Labor Statistics calculates employment and wage estimates for each of the states, MSAs and Balance-of-State areas within each state. As of the June 2006 release, Metropolitan Statistical Area definitions are based on the 2000 Census definitions, and may not be comparable with the old definitions. Also, as of the 2013 release, occupational titles are based on the 2010 Standard Occupational Classification titles. Estimates for some occupations may not be comparable with those from previous years.
In order to better meet local user needs, the North Carolina OES staff has produced wage estimates for other geographies within the state. These estimates incorporate data from the OES survey and are generated utilizing BLS approved methodology. Additional statistics are provided for these local areas, including an entry and experienced wage. The mean of the first third of the wage distribution is used as a proxy for the entry wage. An experienced wage is represented by the mean of the upper two thirds of the wage distribution.
If BLS confidentiality guidelines are not met, occupational employment or wage is suppressed. In counties which did not have enough establishment response to produce 10 or more valid occupational estimates, publication defaults to the occupational wage information for the Workforce Development Board in which the county is located. If the county is located within an MSA, a choice of MSA or Workforce Development Board wages is offered. In Statewide by Industry, limited occupational employment and wage information may be available for some NAICS because of the small number of establishments in the state and confidentiality guideline criteria.
The Bureau of Labor Statistics’ (BLS) Occupational Employment Statistics (OES) program in North Carolina conducts a semi-annual mail survey of employers to produce estimates of occupational employment and wages. This program collects data on hourly and salaried workers, gathering employment and wage information on approximately 800 occupations within statewide industries, and reports the resultant occupational estimates by geographic area and by industry. Military occupations, private households and some agricultural industries are not included in the survey scope. An annual census of Federal and State government employment is used, while local government and non-government establishments are sampled to select representative units.
In this study, estimates based on geographic areas are available at the state, metropolitan statistical area (MSA), county, workforce development board area and economic development region levels. The industry classification corresponds to the four-digit North American Industry Classification System (NAICS). The BLS produces occupational employment and wage estimates at the National level which may be accessed at http://www.bls.gov/oes/current/oes_nat.htm.
The OES survey has been designed to produce estimates using three years of sample data. With approximately 13,000 establishments surveyed each year in North Carolina, a total of 39,000 establishments would be surveyed over a three-year period. Adjustments are applied to previous years’ wage data before combining with current data. For 2004 through 2006 semi-annual release dates, the most recent data set included in the release is approximately one year earlier then the release. For the annual releases beginning in 2007, the most recent data set is from May of the preceding year. The 2001 through 2003 releases were based on an annual survey spread over several months in the fourth quarter of the year. The year date for the survey period is two years earlier than the release date.
Employment is defined as the number of full-time and part-time employees, workers on paid vacation or other type of paid leave, workers assigned temporarily to other units and paid owners, officers and staff of incorporated firms. The survey excludes proprietors, owners and partners of unincorporated firms, unpaid family workers, workers on unpaid leave and contractors and temporary agency employees not on the company payroll.
Wages for the survey are straight time, gross pay, exclusive of premium pay. Base rate, cost-of-living allowances, tips, guaranteed pay, hazardous-duty pay, incentive pay, commissions, production bonuses and on-call pay are included. Excluded is back pay, jury duty pay, overtime pay, severance pay, shift differentials, non-production bonuses and tuition reimbursements.
Earnings data are collected in 12 wage intervals. Employers report the number of employees in an occupation by these intervals. With the exception of the upper open-ended wage interval, a mean wage value is calculated for each wage interval based on occupational wage data collected by the Office of Compensation and Working Conditions. The mean wage value for the upper open-ended wage interval is its lower bound. These interval mean wage values are then attributed to all workers reported in the interval. For each occupation, total weighted wages in each interval are summed across all intervals and divided by the total occupational employment. This calculates an estimated average (mean) hourly wage. Annual wages are calculated by multiplying the hourly wage by 2,040 (52 weeks at 40 hours per week).
There is a small group of occupations, primarily in teaching, where a standard work-year assumption is not considered valid. For this group, the annual wage is calculated directly from the reported data. An hourly wage for these workers cannot be calculated because the number of hours worked is not known. In addition to teachers, the occupations include actors, athletes, coaches, sports officials, flight attendants and pilots.
The Bureau of Labor Statistics calculates employment and wage estimates for each of the States, Metropolitan Statistical Areas and Balance-of-State areas within each state. As of the June 2006 release, Metropolitan Statistical Area definitions are based on the 2000 Census definitions, and may not be comparable with the old definitions. In order to better meet local user needs, the North Carolina OES staff has produced wage estimates for other geographies within the state. These estimates incorporate data from the OES survey and are generated utilizing BLS approved methodology. Additional statistics are provided for these local areas, including an entry and experienced wage. The mean of the first third of the wage distribution is used as a proxy for the entry wage. An experienced wage is represented by the mean of the upper two thirds of the wage distribution.
The 2011 release is transitional between the 2000 and 2012 Standard Occupational Classification systems. Most estimates in this release have 2010 SOC codes and titles; however, there is a small group of rollup codes and titles that incorporate both 2000 and 2010 occupations. Estimates for occupations in this and later releases may not be directly comparable with those for occupations in earlier releases due to changes in the occupational coding structure.
If confidentiality or quality guidelines are not met, the occupational employment and/or wage is not published. Wage information in the counties which did not have enough establishment response to produce 10 or more valid occupational wages defaults to the occupational wage information for the Workforce Development Board in which the county is located. If the county is located within an MSA, a choice of MSA or Workforce Development Board wages is offered. In Statewide by Industry, limited occupational employment and wage information may be available for some NAICS because of the small number of establishments in the state and confidentiality guideline criteria.