Determining correct legal standards depends on previous beliefs about the prevalence of prejudicial engagement and the ability of courts to separate harmful and beneficial relationships.166 Do we believe that the link is generally effective? Do we think that the courts can make decisions with great precision? An illegal rule in itself is most appropriate when one considers that the link is often prejudicial and that the courts cannot precisely separate the harmful and beneficial links. In this case, it is better to condemn all links rather than risk allowing many harmful links, just to save some useful links. Otherwise, a rule of law per se is the most appropriate. Letting through a few harmful links is a small price that allows companies to maintain advantageous relationships without the risk of false conviction. Between these two extremes, the amendment itself illegal (Jefferson Parish), to the rule of reason (Microsoft III), to the amended law per se (Hylton-Salinger).167 Under the legally amended standard agreements of undertaking, it would be considered legal unless there was strong evidence that there were significant anti-competitive effects that outweighed the pro-competitive effects. 168 2. ON THE MODIFIED PER SE APPROACH IN CONTEXT Jefferson Parish, Eastman Kodak v. Image Technical Services,49, which investigated the allegation that Kodak had illegally linked the sale of spare parts for its large-scale photocopiers and micrographs (binders) to the purchase of Kodak repair services (related product). The Supreme Court has accepted the possibility of illegally entering the primary market, even without power in the primary market, which has greatly expanded the scope of illegal employment50. A few decades ago, economists associated with the Chicago School118 explained how attachment could increase comfort and transaction costs.119 They also showed that in theory there are many circumstances in which companies are unable to obtain liaison means to take advantage of a monopoly position in a market to secure additional profits elsewhere – a result that is known as the sole theorem of monopoly profit.