(a) Benefits based on service in employment as defined in subdivisions (9) and (10), section sixteen, article one-a of this chapter, are payable in the same amount, on the same terms and subject to the same conditions as compensation payable on the basis of other service subject to this chapter; except that benefits based on service in an instructional, research or principal administrative capacity in an institution of higher education shall not be paid to an individual for any week of unemployment which begins during the period between two successive academic years, or during a similar period between two regular terms, whether or not successive, or during a period of paid sabbatical leave provided for in the individual's contract, if the individual has a contract or contracts to perform services, in any such capacity for any institution or institutions of higher education for both such academic years or both such terms.

(b) Benefits based on service in employment defined in subdivisions (9) and (10), section sixteen, article one-a of this chapter, are payable in the same amount, on the same terms and subject to the same conditions as benefits payable on the basis of other service subject to this chapter, except that:

(1) With respect to services in an instructional, research or principal administrative capacity for an educational institution, benefits shall not be paid based on such services for any week commencing during the period between two successive academic years or terms, or during a similar period between two regular but not successive terms, or during a period of paid sabbatical leave provided for in the individual's contract, to any individual if such individual performs such services in the first of such academic years or terms and if there is a contract or a reasonable assurance that such individual will perform services in any such capacity for any educational institution in the second of such academic years or terms or after such holiday or vacation period.

(2) With respect to services in any other capacity for an educational institution, benefits shall not be paid on the basis of such services to any individual for any week which commences during a period between two successive academic years or terms if such individual performs such services in the first of such academic years or terms and there is a reasonable assurance that such individual will perform such services in the second of such academic years or terms, except that if compensation is denied to any individual under this subsection and such individual was not offered an opportunity to perform such services for the educational institution for the second of such academic years or terms, such individual is entitled to a retroactive payment of compensation for each week for which the individual filed a timely claim for compensation and for which compensation was denied solely by reason of this clause.

(3) With respect to services described in subdivisions (1) and (2) of this subsection, benefits shall not be paid to any individual for any week which commences during an established and customary vacation period or holiday recess if such individual performs such services in the period immediately before such vacation period or holiday recess, and there is a reasonable assurance that such individual will perform such services in the period immediately following such vacation period or holiday recess.

(4) Benefits payable on the basis of services in any such capacities as specified in subdivisions (1) and (2) of this subsection shall be denied as specified in subdivisions (1), (2) and (3) of this subsection to any individual who performed such services in an educational institution while in the employ of an educational service agency. For purposes of this subdivision the term "educational service agency" means a governmental agency or governmental entity which is established and operated exclusively for the purpose of providing such services to one or more educational institutions.