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Experimental series accounting for January 2026 population control effects

The comparability of Current Population Survey (CPS) labor force measures over time is affected by the annual introduction of updated population estimates from the U.S. Census Bureau. The January 2026 population control adjustment resulted in a decrease of 231,000 people (or 0.1 percent) in the estimated size of the civilian noninstitutional population age 16 and older. However, the adjustment increased the number of people not in the labor force by 1.2 million. The total civilian labor force decreased by 1.4 million (which resulted from a decline of 1.4 million employed people). The adjustment lowered the labor force participation rate by 0.4 percentage point and lowered the employment–population ratio by 0.5 percentage point. The adjustment had little effect on the number of unemployed people (+15,000), and the unemployment rate was unaffected. (The 2026 adjustment was delayed by a month due to the 2025 federal government shutdown and was implemented with the publication of February estimates in March. All CPS data for January were revised at that time to incorporate the new population estimates.)

While the January 2026 adjustment to the population was small relative to adjustments in past years, shifts in the demographic composition of the population were large and had notable impacts on labor force measures. The adjustment reflects changes to the Census Bureau methodology that incorporate updated demographic information about the population from the 2020 Census. This marks a departure from the “blended base” introduced in recent years that combined population totals from the 2020 Census and demographic characteristics from other sources. The adjustment also included updated information showing a decline in net international migration. (For additional information, see the Census Bureau’s Vintage 2025 Methodology and Release Notes documentation. Questions about the population estimates and the methodology used to develop them should be directed to the Census Bureau.)

The January 2026 adjustment affects the comparability of CPS data between December 2025 and January 2026, particularly for estimates of the national labor force, employment, and those not in the labor force. This, in turn, affects comparisons of the labor force participation rate and the employment–population ratio across these months. (Official CPS estimates for December 2025 and earlier months have not been revised, in accordance with usual practice.) Although the population control adjustment appears entirely in the January 2026 CPS data, the update reflects the cumulative change in the population back to the 2020 Census population base.

Experimental series

In 2025, BLS produced new experimental time series measures to account for the size and timing of the large population changes reflected in the January 2025 population control adjustment. For the January 2026 adjustment, BLS continued the production of these series with modifications to the methodology to reflect the changes in demographic composition observed in the January 2026 adjustment. These updated experimental series replace the previous series.

The experimental series use the monthly time series (back to April 2020) available from the Census Bureau’s Vintage 2025 population estimates that form the basis of the January 2026 CPS population control adjustment. As described in the methodology section below, a new step was incorporated this year in addition to the original ratio adjustment used previously.

XLSX table of CPS experimental time series accounting for January 2026 population control effects, April 2020–December 2025

The experimental series are smoother over time, as they do not show the annual effects of the population control adjustments that occur each January in the official series. By applying the compositional factor uniformly over time, the experimental series show lower labor force participation (and employment) relative to the official series. These experimental series show how the timing of changes in the size of the population may have affected the major labor force levels in recent years, as well as how changes in the composition of the population may affect the labor force measures.

These series provide historical context that is roughly consistent with estimates for 2026 that reflect this year’s population control adjustment. The experimental series adjusts data back to April 2020, the decennial census reference point. Data users should not combine these experimental series with official estimates for March 2020 or earlier periods that use a different decennial population base.

Methodology and limitations of these experimental series

The updated methodology introduced in the 2026 experimental series consists of two adjustment factors: a population ratio adjustment factor (like the one used in the 2025 experimental series) and a compositional factor specific to the labor force measure being adjusted (new for the 2026 experimental series).

To construct these experimental series, BLS first calculated a ratio adjustment factor for each month of the series using the new Vintage 2025 population estimates relative to the official population estimates. This step is consistent with the calculations from the previous year and reflects the difference between the updated population estimates and the population estimates used in the official CPS series.

Population ratio adjustment factor for month m =

Population_m _{Vintage 2025}

Population_m _Official

The population ratio adjustment factor was applied to the major labor force levels for each month back to April 2020, including the labor force, employed, unemployed, not in the labor force, and the research series for CPS employment adjusted to the CES concept.

In addition to this population ratio adjustment, BLS introduced a second adjustment factor to better account for changes in the composition of the population. This factor was calculated separately for each labor force measure (LFM)—labor force, employed, unemployed, not in the labor force, and the research series for CPS employment adjusted to the CES concept. (The compositional factor for the population is equal to 1.) The compositional factors are derived using December 2025 CPS data calculated with both the official CPS weights and the new Vintage 2025 population weights. The resulting compositional factor for each measure is then applied uniformly across all months back to April 2020.

Compositional factor LFM =

LFM _{Vintage2025_Dec2025}

[LFM _{Official_Dec2025} × (Population_{Vintage2025_Dec2025}/Population_{Official_Dec2025})]

In summary, for each labor force series month, the calculation involves multiplying the official series by the population ratio factor specific to that month (ratio factor for month m, following the same method as the previous year) and subsequently multiplying by the compositional factor of the labor force measure (compositional factor LFM), which is specific to the labor force measure but remains constant across all months. The experimental labor force participation rate, employment–population ratio, and unemployment rate were then calculated using these experimental labor force measures.

For each month m in the time series,

Experimental estimate = Official estimate_m × Population ratio adjustment factor_m × Compositional factor LFM

These experimental series assume that changes in the total population can be reflected proportionally in the major labor force measures. Importantly, they also assume that all of the compositional change in the 2026 adjustment occurred uniformly across the time series back to April 2020. While the size and approximate timing of the population changes are known, these experimental series do not fully capture the detailed demographic characteristics of recent population changes nor the timing of those changes over the period. Labor force participation and employment outcomes differ across demographic groups, so without more detailed demographic population estimates, these experimental series cannot fully capture how the population changes affected labor force measures. For this reason, BLS has not produced experimental series for other CPS measures or for specific population groups.

Because the methods used to produce the experimental series do not fully account for all demographic changes in the population (and the timing of those changes), the experimental series are not strictly comparable to estimates produced using standard CPS estimation methods.

Data users should note that these experimental series will not match the official CPS estimates published by BLS or available elsewhere on the BLS website.

Last modified date: April 10, 2026