R.I. Gen. Laws § 39-16-13: Tax exemption.

It is hereby declared that the authority and the carrying out of its corporate purposes is in all respects for the benefit of the people of the state and for the improvement of their health, welfare, and prosperity, and the authority will be performing an essential governmental function in the exercise of the powers conferred by this chapter, and the state covenants with the holders of the bonds that the authority shall be required to pay no taxes or assessments or sums in lieu of taxes, except as provided in § 39-16-14, to the state or any political subdivision thereof upon any of the property acquired by it or under its jurisdiction, control, possession, or supervision or upon its activities in the operation and maintenance of the property or upon any earnings, revenues, moneys, or other income derived by the authority, and that the bonds of the authority and the income therefrom shall at all times be exempt from taxation.