Advocates claim a proposed 4 percent surtax on high earners will raise nearly $2 billion per year for education and transportation, but similar tax hikes in other states resulted in highly discretionary rather than targeted spending, according to a new policy brief published by Pioneer Institute. That same result or worse is possible in Massachusetts because during the 2019 constitutional convention state legislators rejected — not just one, but two — proposed amendments requiring that the new revenues be directed to these purposes.