[Excerpt from feature article by Amy Coval, Nami Sumida and Christian Leonard, July 26, 2023]

[....] Data from a variety of sources, like the U.S. Postal Service and government surveys show where some of these people moved. In addition to collecting taxes, the IRS also releases detailed information on where U.S. residents are moving.

The latest data from the IRS is based on the reported mailing address on tax returns filed to the IRS for 2020 and 2021. The tax return data does not cover everyone, as not all U.S. residents are required to file a 1040 tax form, only those who fall into certain income brackets and tax statuses. By looking at year-to-year changes to a filer’s address, the IRS determines whether an individual moved. The agency then publishes data on the total number of movers between any two counties.

The most common destinations for Nutmeggers who moved during the reporting period were mostly other Connecticut counties. 

The greatest number of people that moved into New Haven County were from Fairfield County, with more than 8,000 people leaving Fairfield County for New Haven County. The second greatest influx of movers to New Haven were from Hartford County. Hartford County saw the greatest influx of movers from New Haven, Tolland and Middlesex counties. More than 4,400 people left New Haven County and moved to Hartford between 2020 and 2021.

Mark Abraham, Executive Director of DataHaven said in-state migration within Connecticut is common due the geographical makeup of the state.

“You get a lot of people moving across the county lines especially in places like Connecticut where the counties are dense and it's easy to have a job in one and live in another,” Abraham said. [....]

Net income changes largely follow net migration trends, according to the IRS data. Counties with population increases in 2020 and 2021 typically gained income, while counties with overall population declines generally lost income.

Abraham stressed that while the narrative behind the IRS data can sometimes suggest certain amounts of wealth leaving the state, it is important to remember that it is the people leaving the states — not the jobs. He said if a Yale surgeon were to make a salary of $1 million. If that surgeon retires and leaves the state, that salary is not going with the person, he said, it is staying right here in the Nutmeg State. [....]

The IRS data provides only the total income, so it is possible that some of the outliers are driven by one particularly wealthy household moving from one county to another. We’ve included only cases where at least 50 households moved between counties to account for that, but a very rich family still might skew the results.