Google’s Hidden Empire: This paper presents striking new data about the scale of Google’s involvement in the global digital and corporate landscape, head and shoulders above the other big tech firms. While public attention and some antitrust scrutiny has focused on these firms’ mergers and acquisitions (M&A) activities, Google has also been amassing an empire of more than 6,000 companies which it has acquired, supported or invested in, across the digital economy and beyond. The power of Google over the digital markets infrastructure and dynamics is likely greater than previously documented. We also trace the antitrust failures that have led to this state of affairs. In particular, we explore the role of neoclassical economics practiced both inside the regulatory authorities and by consultants on the outside. Their unduly narrow approach has obscured harms from vertical and conglomerate concentrations of market power and erected ever higher hurdles for enforcement action, as we demonstrate using examples of the failure to intervene in the Google/DoubleClick and Google/Fitbit mergers. Our lessons from the past failures can inform the current approach towards one of the biggest ever big tech M&A deals: Google’s $32 billion acquisition of the Israeli cloud cybersecurity firm Wiz.