Migration Trends FAQs

Q: What is the source of the polygons used to define/geofence the Cities and Towns?

A: We use Census Places polygons, taken from this source: https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2022&layergroup=Places

Q: Why does my town not appear in Placer’s Migration Trends ‘Cities and Towns’?

A: A total of just over 22,000 Cities & Towns is supported by our Migration trends (after having filtered out ones that are too small, e.g. lacking an adequate panel). Most likely your town has too small a population for us to be able to establish data from a reliable panel in it, throughout the year.

Q: Do Placer’s Migration numbers take into account migration from or to Puerto Rico?

A: As of V3.1 (August release) Yes - in geographies where relevant, we incorporate migration counts derived from Census data, allowing us to include migration to and from Puerto Rico

Q: How does Placer address the migration of non-DMA and non-CBSA areas?

A: The v3.1 release of the Migration trends feed introduces the following new DMA/CBSAs to answer this exact question:
non-DMA : 111 - represents non-DMA covered areas of Alaska. Migrations identified as occurring to/from those ‘non-DMA covered’ locations are counted as part of this new ‘non-DMA’.
non-CBSA: XX111 - Is a new formatted code of aggregating CBSAs representing the non-CBSA areas of any state includes such areas. The code of this new CBSAs is a concatenation of the FIPS state code and ‘111’. For example Florida FIPS state code is 12, so the non-CBSA areas in Florida are aggregated into CBSA code 12111.

Q: How do you count an individual that migrated towards the end of last month’s report, but then turned out to have left the destination of migration (i.e. returned home ) right after the report was published?

A: Such an “edge case” will be corrected in the following month’s migration report. On calculating migration for the following month the individual will be identified as not having met the migration criteria of a minimal 2 month stay, so will be filtered out of the month in which his migration was previously reported. This correction will retroactively reflect that the individual did not migrate (to the region previously reported), and the migration data for that region will be adjusted accordingly.

Q: Can Migration Data update historically/retroactively?

A: Yes, historical migration data may update retroactively to reflect ‘real world’ changes that transpired, e.g. a person that moved (counted towards migration) but then returned after less than 5 months (therefore did not migrate in reality). There may be more retroactive updates in the latest month reported, but they subside significantly the further you look back; e.g. typically negligible tiny changes to historical data 6 months and older. We recommend that customers using the Migration Trends report will refresh the historical data each month, upon receiving the new report.

Q: What’s the difference between Permanent Residents and Seasonal Visitors?

A: Permanent residents are individuals residing in the chosen area for a minimum of 5 months, indicating a likelihood of long-term residency. On the other hand, Seasonal Visitors are those who relocate to stay for a duration ranging from 2 to 5 months, a common scenario for students, snowbirds, and seasonal workers.

Q: What happened to the previously used “Adjusted Population” metric?

A:We have updated the name of this metric, transitioning from "Adjusted Population" to "Permanent Residents Population," to emphasize its altered calculation. The revised metric now specifically includes individuals who have relocated to the area of interest and remained for a minimum of 5 months, eliminating 'seasonal migrants' from the count, in contrast to the previous 2-month threshold.

Q: Why is it significant to display "Seasonal Visitors"? What is their significance, and who has an interest in them?

A: We distinctively tally and display Seasonal Visitors due to their significance in certain scenarios. For instance, in a tourist town where the population surges fourfold in the summer because of a substantial seasonal influx of vacationing visitors, who stay for a few months and significantly impact the local economy.

Q: How can Net Migration be displayed from 2 or 3 months ago in V4, when it relies on Permanent Residents, requiring a five-month history?

A: Migration data usually changes slowly, with month-to-month variations being minimal or following a predictable annual pattern. Leveraging our extensive history of Placer Migration data, including the 'old' V3.2 data reporting movements from two months ago, we effectively bridge the three-month gap between the last recorded movements of individuals who migrated five months ago and the subsequent three months. Utilizing historical data, recent up-to-date migration data, and established forecasting/extrapolation algorithms, we predict the last three months' Net Migration, Permanent Residents Population, and Visiting Seasonals.