Washington state has long found itself labeled as having one of the least equitable tax structures of any state, something Microsoft co-founder Bill Gates affirmed in a recent blog post calling for an income tax.

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“The truth is, I’ve been pushing for a fairer tax system for years,” Gates penned. “It was nearly two decades ago that my dad and I started calling for an increase in the federal estate tax and for an estate tax in our home state of Washington, which has the most regressive tax system in the country.”

Gates used that point to emphasize the need for an improved tax system both in Washington and the U.S., with a special focus on fairly taxing the country’s wealthiest earners.

“The wealth gap is growing,” he noted. “The distance between top and bottom incomes in the United States is much greater than it was 50 years ago. A few people end up with a great deal —I’ve been disproportionately rewarded for the work I’ve done — while many others who work just as hard struggle to get by.”

Gates went on to lay out what he views as a hard truth: That the U.S. government at its core doesn’t collect enough in taxes. He backs that up with data stating that while the federal government collects roughly 20 percent of GDP in taxes, it spends 24 percent.

To bridge that gap, he proposes raising the estate tax, and closing certain loopholes “many wealthy people take advantage of.”

“I don’t see any reason to favor wealth over work the way we do today,” said Gates. “A dynastic system where you can pass vast wealth along to your children is not good for anyone; the next generation doesn’t end up with the same incentive to work hard and contribute to the economy.”

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In addition to the estate tax, Gates also called for removing the cap on how much income is subject to Medicare taxes, taxing long-held massive fortunes, and making state and local taxes more equitable in the form of an income tax in Washington state.

“It isn’t always popular to stand up for higher taxes, so it’s great that many Americans are having this conversation,” he stated. “I want to be as clear as possible about my views.”