acquisition is likely to have the effect of substantially lessening competition in a market for Telecommunications Services. 2) Where the Authority decides to initiate a regulatory proceeding for any of the three cases presented in Sub‐Article 1 of this Article, it shall do so in accordance with the procedure established in Articles 34 and 36 through 38 of the Proclamation, and this Directive. 7. Market Definition in a Market Review 1) The Authority shall endeavor to perform a Market Review every three (3) years to define markets susceptible to regulation, and designate operators as having SMP in those markets, if applicable. 2) The purpose of a Market Review shall not be to define all telecommunications markets. Instead, the Market Review shall define only markets that shall be susceptible to regulation. 3) The following three-criteria test shall be applied to identify a market susceptible to ex ante regulation. a) There are high and non‐transitory barriers to entry or expansion; b) The market structure does not tend towards effective competition within a relevant time horizon; and, c) The application of competition law alone would not adequately address the market failure concerned. 4) The Authority shall use a forward‐looking or prospective approach, to define these markets. A prospective approach involves assessing the market dynamics and attempting to anticipate the nature of competition in the near to medium term. 8. Market Definition as Part of an Investigation Into Alleged Anti‐Competitive Practices When investigating allegations of anti‐competitive practices, the Authority shall define a relevant market using a backward‐looking or retrospective approach. A retrospective approach considers a period of time equivalent to the period of the alleged misconduct. 9. Market Definition as Part of a Review of a Mergers and Acquisitions Notification The Authority may define a relevant market as part of a review of a Mergers and Acquisitions Notification. In that case, the Authority shall use a prospective approach, but considering the change in market structure or concentration, that would result with the proposed merger or acquisition. PART FOUR GENERAL APPROACH TO DEFINE RELEVANT MARKETS 10. The Relevant Product Market 1) When defining a relevant market, the Authority shall include all services that are considered to be close substitutes, regardless of the underlying technology used to provide it. These services compete directly with each other, so that, the potential demand ‐ or supply‐side substitution between them will constrain their prices. 6