The February 16, 2017 Census Bureau and HUD report estimated January U.S. privately owned housing starts at a seasonally adjusted annual rate of 1,246,000 units. That is an annualized pace, not the number started during January. The reported monthly change was minus 2.6 percent, but its 90 percent sampling margin was 11.0 percentage points. [nrc_201701]

That interval includes zero, leaving the direction statistically uncertain. The same distinction applies to completions: their annualized rate was 1,047,000 units, with an estimated monthly change of minus 5.6 percent and a 90 percent sampling margin of 8.0 percentage points. Neither comparison established an actual decline, and statistical uncertainty does not prove that the actual change was zero. [nrc_201701]

The baseline also changed between releases. On January 19, the agencies initially estimated December starts at a seasonally adjusted annual rate of 1,226,000 units. The February report used a revised December rate of 1,279,000. Comparing January with the older December number would mix vintages instead of reproducing the comparison in the February release. [nrc_201701][nrc_201612]

Permits were a separate measure: housing units authorized, not started or completed. Their January annualized rate was 1,285,000, up an estimated 4.6 percent with a 2.0-percentage-point 90 percent sampling margin. That interval excludes zero. All these intervals address sampling variability only; the agencies also warn about nonsampling error. The reports therefore support different degrees of certainty for different construction stages. [nrc_201701]

Source documents

  1. CB17-23: Monthly New Residential Construction, January 2017https://www.census.gov/construction/nrc/pdf/newresconst_201701.pdf
  2. CB17-09: New Residential Construction in December 2016https://www.census.gov/construction/nrc/pdf/newresconst_201612.pdf