Data Releases

IRS: Davidson County among national leaders in attracting residents from out of state

Davidson County was among the leaders nationally in attracting residents from out of state in 2017-2018, according to new data from the Internal Revenue Service (IRS).

Nearly 17,000 households representing an estimated 25,000 people (see methodology below) moved to Davidson County from other states in 2017-2018, accounting for the majority of all US-based moves to the county (61%). Davidson County’s net gain, or inflow-outflow, of an estimated 3,358 households from out of state ranked 16th among the 100 largest counties in the country. Maricopa County, AZ (Phoenix) had the largest net gain in households at 21,267, followed by Clark County, NV (Las Vegas) at 15,628, and King County, WA (Seattle) at 10,718. Denver and Wake County (Raleigh) rounded out the top five.

Since nominal change tends to favor large counties—i.e. more people, more moves—it can be helpful to normalize the data to account for differences in total population. Looking at net migration of households from out of state relative to total population, Davidson County jumps up to #7 (Denver is first). In other words, people moving to Davidson County from out of state are having a more significant impact on the size of the overall population here compared to the impact of out-of-state migration in most other large, growing counties.

Where are people coming from?

In terms of migration the top “donor” states to Davidson County ranked by inflow of households (with a minimum of 500) in 2017-2018 were:

  1. Florida 1,206
  2. California 1,152
  3. Texas 847
  4. Illinois 761
  5. Georgia 611
  6. New York 598
  7. Alabama 547
  8. Kentucky 508

In net terms (inflow-outflow) Davidson County gained the most households from Illinois (446), California (367), and Florida (337).

The top ten donor counties to Davidson County were:

  1. Rutherford County 2,183
  2. Williamson County 2,045
  3. Sumner County 1,239
  4. Wilson County 1,022
  5. Shelby County 606
  6. Montgomery County 481
  7. Cook County (IL) 465
  8. Los Angeles County (CA) 437
  9. Robertson County 364
  10. Cheatham County 344

The top ten donor counties from out of state were:

  1. Cook County (IL) 465
  2. Los Angeles County (CA) 437
  3. Fulton County (GA) 239
  4. Harris County (TX) 201
  5. Dallas County (TX) 197
  6. Jefferson County (AL) 181
  7. New York County (NY) 166
  8. San Diego County (CA) 160
  9. Maricopa County (AZ) 158
  10. Kings County (NY) 158

Nearly one out of every five households moving to Tennessee from other states went to Davidson County, followed by Shelby County (13%) and Montgomery County (8%).


The IRS publishes annual data showing the number of tax returns, exemptions, and total adjusted gross income reported in each state and county and then matches addresses in consecutive years of filings to identify migrants. Analysts use these returns to estimate households and exemptions to estimate people, but they are not matched 1:1.

For example, multiple returns can be filed from the same address, and not all exemptions are people. Generally, returns are a more accurate proxy for households than exemptions are for people, which is why most analysts focus on returns when reporting the data. Time periods are expressed in hyphenated years (e.g., 2017-2018) due to tax filing deadlines. The 2017-2018 data set includes reported income earned in Tax Year 2017 only but could reflect a move in 2018 during the filing period for most returns, January-April 15, 2018. Since a move could occur at any time between when the Tax Year 2016 return was filed and when the Tax Year 2017 return was filed it must be expressed as two hyphenated calendar years.

Finally, not everybody is required to file a tax return, meaning the IRS data does not reflect the total population. Please see the user guide posted on the IRS website for a more detailed explanation of data limitations and appropriate interpretation.

Data Releases

Which county is the most charitable in Tennessee?

The latest round of charitable contribution statistics, as well as a wide range of other useful data generated from 2017 tax returns, are now available from the IRS Statistics of Income (SOI) program. This annual data set is extremely useful for academic purposes, including studies of income inequality, concentration of wealth, and tax incidence. But there are also important practical uses, especially for non-profits and others engaged in fundraising. Zip code data is available, which can be used to target areas where taxpaying households are reporting greater levels of charitable giving (data is also available for states, metro/micro areas, counties, and congressional districts).

Here’s a summary of charitable contributions for Tennessee’s largest counties:

Summary data can be calculated in several ways. Here I’ve ranked large counties (100,000+ in population) by the share of tax returns reporting deductions for charitable contributions. For example, 38.1% of taxpaying households in Williamson County reported deductions for charitable contributions in 2017, which is by far the highest rate among all counties in TN and more than twice the statewide rate (16.8%). That shouldn’t be too surprising given the median household income in Williamson County of $103,543, which is also, by far, highest among counties in the state (Wilson is second highest at $66,123). Charitable contributions, calculated as a share of tax returns (.85) or as a share of total income (.53), and household income are positively correlated, as you might expect.

Here’s a look at which counties of any size exceed the statewide rate (16.8%) of tax returns with charitable contributions:

I’ve bolded two smaller counties, Fayette and Loudon, that join many of the largest counties in the state on this list. Fayette County, in particular, stands out at 25.8%, the second highest share of taxpaying households reporting charitable contributions.

Same idea here, but ranked by charitable contributions as a share of total income:

Shelby County tops this list at 3.6%, compared to the statewide rate of 2.4%. In other words, deductions for charitable contributions reported by taxpaying households in Shelby County in 2017 were equivalent to 3.6% of total income reported.

Finally, statistics are also available by income bracket. Here’s a look at counties that exceed the statewide rate (75.5%) of returns reporting charitable contributions among households with $200,000 or more in total income reported:

Shelby County tops that list at 82.4%, slightly ahead of Williamson County. Shelby County also ranks highly on charitable contributions as a share of total income among $200,000+ households that exceed the statewide rate of 3.7%:

Of course, not all charitable contributions (or income) are reported on tax returns. Further, tax deductions do not adequately reflect all charitable activity performed by residents of a community. Significant contributions are made in non-monetary ways.

That said, which county is the most charitable in Tennessee, based on this newly published data for 2017? I’m giving the nod to Shelby County, but its highest-income households need to step it up a bit to catch Hamilton. My second overall goes to Williamson, but I’m curious about its absence from that last table on high-income giving.