WASHINGTON — High school dropouts are costing some $1.8 billion in lost tax revenue every year, education advocates said in a report released Monday.

If states were to increase their graduation rates, state and federal lawmakers could be plugging their budgets with workers’ taxes instead of furloughing teachers, closing drivers-license offices, and cutting unemployment benefits. While advocates tend to focus on the moral argument that all children deserve a quality education, they could as easily look at budgets’ bottom lines.