Article 21, TEACHERS

Paragraph (1) provides that, U a resident of one Contracting State is invited by the other Contracting State, a political subdivision or local authority thereof, or by a university or other recognized educational

institution in that other Contracting State to come to the other Contract­ ing State for a period not expected to exceed 2 years tor the purpose or teaching or engaging in research, or both, at a university or other recog­ nized educational institution, and i! such resident comes to that other

Contracting State primarily tor such purpose, his income from personal services for teaching or research at such university or educational in­ stitution will be exempt from tax by that other Contracting State for a period not exceeding 2 years from the date or his arrival in that other

Contracting State.

Since a temporary vi'sit may be or such a duration that an individual may lose his status as a resident or the Contracting State or which he was a resident at the time he became eligible for the benefits or this Article, the individual need only be a resident or such Contracting State at the beginni g o! his visit. However, 1! the individual becomes a citizen of, or acquires im igrant status in, the other Contracting State, that other Contracting State may tax the individual without regard to this Article, Se paragraphs (3) and (4)(b) or Article 6 (General Rules or Taxation), U the individual's visit exceeds a period or 2 years from the date or his arrival, the exemption applies only to the income received by the individual before the expiration or such 2-year period, H:)wever, it the period or the visit had been expected to exceed two years then the exemption does not apply to any or the income earned, H::>wever, il an individual who otherwise meets the requirements of this Article expects to visit tor a period or two years tor the purpose o! teaching and for a subsequent period o!, !gr example, two years tor purposes described in paragraph-{1) of Article 22 (Students and Trainees), then pursuant to paragraph (4) of Article 22 the exemption provided by this Article does apply,

.A person who visits a Contracting State tor the purposes explained in this Article and meets the qualifications contained in it may again claim its benefits il he first reestablishes his residence in the other

Contracting State, In such a case, the person claiming these benefits. on a subsequent oc asion must first satisfy the competent authority of the first-mentioned Contracting State that he had become a bona fide resident of the other Contracting State !or a substantial period of time.

Pursuant to paragraph (2 ), this Article does not apply to income from research undertaken not in the general interest (i, e., public interest) but primarily for the private benefit of a specific person or persons other than the person performing the research. For example, research projects which are undertaken to discover or perfect product processes, designs, etc,, which are expected to be commercially exploited by the researcher or his present (or former) employer do not qualify under this Article,