I noticed the 3 year for 2010-2012 was released Feb 17, 2014. Is mid February a standing schedule for releasing 3 year data?
Does the IPUMS team simply divide the weight by three when releasing the three year file of the ACS?
Any update on when the 2013 ACS multi-year data will be released?
Generally IPUMS-USA does release multi-year ACS samples within 2 months of their initial release by the Census Bureau. This year the IPUMS-USA team is working on improving their data creation process.This will ultimately improve the IPUMS-USA project as a whole, but with the unfortunate side-effect of delaying the release of the 2013 multi-year ACS data files. While there is no current estimated release date for these samples, I do not believe they will become available through IPUMS-USA before April of 2015. However, because the multi-year data files are simply a concatenation of the single-year ACS data files, you can construct the multi-year files yourself. All respondents from the 2011, 2012, and 2013 1-year ACS files are combined to create the 3-year file. This means you can simply select the 2011, 2012, and 2013 1-year ACS datasets from the IPUMS-USA data selection menu, adjust dollar values to the most recent year in the 3-year set (using YEAR and an adjusted CPI99 variable), and divide all weight values by 3. While the Census Bureau does use more complex methods for generating multi-year weights (see Weighting Methodology from the 2012 3-year Accuracy Statement), simply dividing by three is the primary adjustment and provides extremely similar values to the Census Bureau calculated weights. You can verify this by trying to match the 2011-2013 PUMS Estimates for User Verification. If you are still uncertain about this combination method, I would recommend replicating your analysis using the combined 2010 to 2012 ACS samples and compare your results with the actual 2012 3-year ACS sample.
I hope this helps.