Revenue from Oregon estate taxes has increased more than sixfold over the past two decades, rising from less than $50 million annually to around $300 million.

It’s not that more people are dying — though Oregon does have one of the oldest populations of any state. Rather, state economists say, estate tax payments are rising because more wealthy people are dying and the size of their fortunes is much larger than in past years.

“The majority of the revenue increase is due to a relatively small number of very high valued estates,” said state economist Josh Lehner.

Who’s among this small group? It’s difficult to say, because Oregon closely guards taxpayers’ information from public inspection, even after death.

Estate taxes — assessed on wealth and property passed on to heirs — are a relatively small portion of total state revenue. While $300 million in estate taxes is certainly a lot of money, it’s a lot less than the $8.6 billion in personal income taxes Oregon expects to collect this year.

Oregon taxes estates worth more than $1 million, a low threshold compared to other jurisdictions. The federal estate tax kicks in for estates worth more than $13.6 million, by comparison. Washington state taxes estates valued at more than $2.2 million.

Estate taxes owed can vary widely based on the financial decisions the deceased made in life. But Lehner said that some people who work to shield their estates from federal taxes are nonetheless subject to the Oregon tax because of the lower threshold.

Just a few thousand Oregon estates exceeded the state’s threshold in 2021, according to the latest state data. That’s more than double the number that paid the tax a decade earlier but a small fraction of the roughly 42,000 Oregonians who die each year.

Oregon’s tax rate on estates rises gradually from 10% for those valued above $1 million to 16% for the portion of an estate valued above $9.5 million.

A few factors may be playing a role in the growing number of estates subject to Oregon’s tax. The $1 million tax threshold hasn’t changed since 2006, and inflation has pushed up incomes and investment valuations since then.

Oregon home prices have climbed, too. That pushed more estates above that million-dollar threshold and increased the number of filings, though the state hasn’t quantified the effect.

By itself, though, more estates hitting Oregon’s million-dollar threshold for estate taxes doesn’t explain the tremendous rise in revenue.

Instead, Lehner says the rapid rise in estate taxes is due to a rapid increase in the wealth accumulated by Oregon’s most affluent.

“Yes, more estates does increase revenue,” he said. “However, the majority of the revenue, and the majority of the increase in revenue, is due to those really high-valued estates.”

This is Oregon Insight, The Oregonian’s weekly look at the numbers behind the state’s economy. View past installments here.

-- Mike Rogoway covers Oregon technology and the state economy. Reach him at mrogoway@oregonian.com.