Valletti, who is also a Professor of Economics at the Imperial College Business School and the University of Rome Tor Vergata, discussed the EC's investigation into the Facebook-WhatsApp merger during the panel. Facebook, he said, had "lied" to European regulators about its ability to absorb WhatsApp's user data, but the larger issue was market definition.

"Would the decision on the merger have changed had the Commission known that information at the time?" asked Valletti, who joined theEC in 2016. "At the time, the Commission defined the relevant market as non-search advertising. This is a huge market. In that ocean, even Facebook doesn't have a lot of market power. If instead the market definition had been, for instance, advertising on social networks, [it's]likely theywould have concluded that Facebook would have been dominant in that particular market, and that integrating that useful information from [WhatsApp] could have enhanced its market power." Valletti also stressedthe importance of having individual-level data when discussing issues like competition at the advertising market, and not just looking at market shares.

Pasquale and Taplin, meanwhile, criticized U.S. antitrust authorities, with Taplin saying that digital platforms have "done very well because they have a certain regulatory capture" and Pasquale remarkingthat "U.S. antitrust policy is rapidly becoming a pro-trust policy."

As an example of this "pro-trust" policy, Pasquale cited the FTC's lawsuit against online contact lens retailer 1-800 Contacts . 1-800 Contacts was sued by the FTC last yearfor having reached agreements with 14 other online contact lens sellers that they would not advertise to customers who had searched for 1-800 Contacts online."You would imagine that given the power of these [companies], and given the activity in Europe and many other nations, our enforcers would be extremely concerned about these platforms. They are-they're concerned about little companies hurting the platforms," he said.

The FTC, added Pasquale, had pursued the 1-800 Contacts case aggressively. "I'm not here to comment on the merits of this case, but I think that the choice of this enforcement target speaks volumes. What does it say? It says that if small firms arebeing exploited or hurt by a big digital behemoth, or think [they]are, don't try in any way to coordinate or maintain your independence. What you should do is all combine and merge and become a giant, say, contacts firm. In the media, they should all combine and merge and maybe all be bought by Comcast, so that then they can negotiate with Google in a way that they are relatively of the same size and power. That's the pro-trust message we're getting under current non-enforcement U.S. antitrust policy."