Technical Note This release presents labor force and unemployment data from the Local Area Unemployment Statistics (LAUS) program (tables 1 and 2) for 387 metropolitan statistical areas and metropolitan New England City and Town Areas (NECTAs), plus 7 areas in Puerto Rico. Estimates for 38 metropolitan and NECTA divisions also are presented. Nonfarm payroll employment estimates from the Current Employment Statistics (CES) program (tables 3 and 4) are provided for most of the same areas. State estimates were previously published in the news release, Regional and State Employment and Unemployment, and are republished in this release for ease of reference. The LAUS and CES programs are both federal-state cooperative endeavors. Labor force and unemployment--from the LAUS program Definitions. The labor force and unemployment data are based on the same concepts and definitions as those used for the official national estimates obtained from the Current Population Survey (CPS), a sample survey of households that is conducted for the Bureau of Labor Statistics (BLS) by the U.S. Census Bureau. The LAUS program measures employment and unemployment on a place-of-residence basis. The universe for each is the civilian noninstitutional population 16 years of age and older. Employed persons are those who did any work at all for pay or profit in the reference week (the week including the 12th of the month) or worked 15 hours or more without pay in a family business or farm, plus those not working who had a job from which they were temporarily absent, whether or not paid, for such reasons as labor-management dispute, illness, or vacation. Unemployed persons are those who were not employed during the reference week (based on the definition above), had actively looked for a job sometime in the 4-week period ending with the reference week, and were currently available for work; persons on layoff expecting recall need not be looking for work to be counted as unemployed. The labor force is the sum of employed and unemployed persons. The unemployment rate is the number of unemployed as a percent of the labor force. Method of estimation. Estimates for states, the District of Columbia, the Los Angeles-Long Beach-Glendale metropolitan division, and New York City are produced using time-series models with real-time benchmarking to national CPS totals. Model-based estimates are also produced for the following areas and their respective balances: the Chicago-Naperville- Arlington Heights, IL Metropolitan Division; Cleveland-Elyria, OH Metropolitan Statistical Area; Detroit-Warren-Dearborn, MI Metropolitan Statistical Area; Miami-Miami Beach-Kendall, FL Metropolitan Division; and Seattle-Bellevue-Everett, WA Metropolitan Division. Modeling improves the statistical basis of the estimation for these areas and provides important tools for analysis, such as measures of errors and seasonally adjusted series. For all other substate areas in this release, estimates are prepared through indirect estimation procedures using a building-block approach. Employment estimates, which are based largely on "place of work" estimates from the CES program, are adjusted to refer to place of residence as used in the CPS. Unemployment estimates are aggregates of persons previously employed in industries covered by state unemployment insurance (UI) laws and entrants to the labor force data from the CPS. The substate estimates of employment and unemployment, which geographically exhaust the entire state, are adjusted proportionally to ensure that they add to the independently estimated state or balance-of- state totals. A detailed description of the estimation procedures is available from BLS upon request. Annual revisions. Labor force and unemployment data shown for the prior year reflect adjustments made at the beginning of each year, usually implemented with the issuance of January estimates. The adjusted model-based estimates typically reflect updated population data from the U.S. Census Bureau, any revisions in other input data sources, and model re-estimation. All substate estimates then are re-estimated using updated inputs and adjusted to add to the revised model-based totals. In early 2015, a new generation of time-series models was implemented, resulting in the replacement of data back to the series beginnings. At the same time, enhancements were made to the substate estimation methodology, and more timely inputs from the American Community Survey were incorporated. Employment--from the CES program Definitions. Employment data refer to persons on establishment payrolls who receive pay for any part of the pay period that includes the 12th of the month. Persons are counted at their place of work rather than at their place of residence; those appearing on more than one payroll are counted on each payroll. Industries are classified on the basis of their principal activity in accordance with the 2012 version of the North American Industry Classification System. Method of estimation. CES State and Area employment data are produced using several estimation procedures. Where possible these data are produced using a "weighted link relative" estimation technique in which a ratio of current-month weighted employment to that of the previous-month weighted employment is computed from a sample of establishments reporting for both months. The estimates of employment for the current month are then obtained by multiplying these ratios by the previous month's employment estimates. The weighted link relative technique is utilized for data series where the sample size meets certain statistical criteria. For some employment series, the sample of establishments is very small or highly variable. In these cases, a model-based approach is used in estimation. These models use the direct sample estimates (described above), combined with forecasts of historical (benchmarked) data to decrease volatility in estimation. Two different models (Fay-Herriot Model and Small Domain Model) are used depending on the industry level being estimated. For more detailed information about each model, refer to the BLS Handbook of Methods. Annual revisions. Employment estimates are adjusted annually to a complete count of jobs, called benchmarks, derived principally from tax reports that are submitted by employers who are covered under state unemployment insurance (UI) laws. The benchmark information is used to adjust the monthly estimates between the new benchmark and the preceding one and also to establish the level of employment for the new benchmark month. Thus, the benchmarking process establishes the level of employment, and the sample is used to measure the month-to-month changes in the level for the subsequent months. Seasonal adjustment. Payroll employment data are seasonally adjusted for states, metropolitan areas, and metropolitan divisions at the total nonfarm level. For states, data are seasonally adjusted at the supersector level as well. Revisions of historical data for the most recent 5 years are made once a year, coincident with annual benchmark adjustments. Reliability of the estimates The estimates presented in this release are based on sample surveys, administrative data, and modeling and, thus, are subject to sampling and other types of errors. Sampling error is a measure of sampling variability--that is, variation that occurs by chance because a sample rather than the entire population is surveyed. Survey data also are subject to nonsampling errors, such as those which can be introduced into the data collection and processing operations. Estimates not directly derived from sample surveys are subject to additional errors resulting from the specific estimation processes used. The sums of individual items may not always equal the totals shown in the same tables because of rounding. Unemployment rates are computed from unrounded data and thus may differ slightly from rates computed using the rounded data displayed in the tables. Labor force and unemployment estimates. Measures of sampling error are not available for metropolitan areas or metropolitan divisions. Model-based error measures for states are available on the BLS website at www.bls.gov/lau/lastderr.htm. Measures of nonsampling error are not available for the areas contained in this release. Information on recent data revisions for states and local areas is available online at www.bls.gov/lau/launews1.htm. Employment estimates. Measures of sampling error are available for metropolitan areas or metropolitan divisions upon request. Measures of sampling error for states down to the supersector level are available on the BLS website at www.bls.gov/sae/790stderr.htm. Measures of nonsampling error are not available for the areas contained in this release. Information on recent benchmark revisions is available online at www.bls.gov/sae/. Area definitions The substate area data published in this release reflect the delineations issued by the U.S. Office of Management and Budget on February 28, 2013. Data reflect New England City and Town Area (NECTA) definitions, rather than county-based definitions, in the six New England States. A detailed list of the geographic definitions is available online at www.bls.gov/lau/lausmsa.htm. Additional information Estimates of unadjusted and seasonally adjusted labor force and unemployment data for states, census regions and divisions, and seven substate areas are available in the news release, Regional and State Employment and Unemployment. Estimates of labor force and unemployment for all states, metropolitan areas, counties, cities with a population of 25,000 or more, and other areas used in the administration of various federal economic assistance programs are available on the Internet at www.bls.gov/lau/. Employment data from the CES program are available on the BLS website at www.bls.gov/sae/. Information in this release will be made available to sensory impaired individuals upon request. Voice phone: (202) 691-5200; Federal Relay Service: (800) 877-8339.