- The paper reveals that Google commands 71.8% of horizontal search volume and over 50% market share in key vertical segments.
- It employs a robust methodology using observational browser data and re-crawling techniques to compare horizontal and vertical search patterns.
- The findings bolster regulatory debates by highlighting Google's gatekeeping power, with over 80% of navigational queries funneled to its own products.
Investigating Google Search's Market Shares Under Horizontal and Vertical Segmentation
In the paper titled, "Market or Markets? Investigating Google Search's Market Shares Under Horizontal and Vertical Segmentation," Hu et al. embark on an empirical analysis to dissect Google Search's market power by accounting for both horizontal and vertical segmentation of online search queries. In light of ongoing antitrust litigation and regulatory debates, this research aims to elucidate the extent of Google’s dominance and its implications across various domains of online search.
Methodology and Data
The authors leverage observational trace data collected via a browser extension installed by a panel of US residents. This data includes detailed web browsing histories and snapshots of the Google Search Engine Result Pages (SERPs). By examining queries and search patterns across both Google and Bing, the paper differentiates horizontal searches—general web search engines—from vertical searches—specialized search engines catering to domains such as shopping, news, or travel.
For horizontal search segmentation, the analysis primarily focuses on Google and Bing, as these engines account for 97% of participants’ search activities in this segment. To further ensure a comprehensive view, they include searches on specific Google vertical search products within the horizontal search analysis.
In vertical segmentation, the paper employs a dual approach: identifying searches on nearly 50,000 vertical search engines and categorizing them into 90 segments based on FortiGuard's mapping while also assigning Google and Bing queries to these vertical segments through direct observation and re-crawling.
Key Findings
Horizontal Market Analysis
- Market Share: Google Search dominates with 71.8% of the search volume among the sampled horizontal search engine queries, consistent with estimated ranges of 61-80% from other recent statistics.
- Participant Preference: A significant 79.3% of participants show a strong preference toward Google Search as their primary engine.
- Search Behavior Stability: The paper reveals consistent usage trends over the observation period, which underscores Google's entrenched position.
Vertical Market Analysis
- Market Shares: Google products (both general and specialized) capture over 50% of search shares in 21 of the top 30 vertical segments including key informational domains like Health and Wellness, Entertainment, and Reference.
- Gatekeeping Power: Google's gatekeeping role is substantiated by the finding that over 80% of navigational queries—critical for vertically specialized search engines—are dominated by Google. Furthermore, 24 out of 30 vertical segments see more than 50% of search sessions starting on Google products.
Implications and Future Directions
The empirical insights provided by this paper have significant implications for ongoing antitrust scrutiny and the interpretation of Google’s market power. The data suggests that Google's influence extends beyond general search into multiple vertical domains, highlighting its capability to leverage its general search dominance to steer substantial traffic towards its own vertical offerings. This finding challenges Google's claim that vertical search engines provide significant competition in online search.
From a regulatory perspective, the paper’s results bolster arguments for considering structural remedies—such as separating Google's general and vertical search functions—or behavioral remedies aimed at curtailing exclusionary practices. This stratagem could mitigate Google's extensive gatekeeping power and foster more competitive online search ecosystems.
Given the rapid advancements in AI and the integration of generative models like those seen in ChatGPT, future developments in search engine technology may necessitate updated methodologies to continue scrutinizing market dynamics accurately. Although initial implementations of AI-powered functionalities in search engines have not drastically changed market shares yet, the longitudinal impact of such technologies remains an open question.
Limitations
While the paper is robust in its design and execution, the authors acknowledge potential limitations including the lack of mobile and non-US data, underrepresentation of non-Google vertical search engines, and the necessity to rely on snapshot data for analyses of non-Google SERPs. These factors suggest that the current conclusions, while compelling, may represent lower-bound estimates of Google's market power.
Conclusion
Hu et al.'s exploration into the market shares of Google Search under horizontal and vertical segmentation sheds new light on the pervasive influence of Google's search products. The paper not only broadens our empirical understanding of online search market dynamics but also provides critical evidence to inform regulatory policies aimed at ensuring competitive digital marketplaces.
By rigorously analyzing both actual user behavior and search engine market shares, this work significantly contributes to our understanding of how entrenched market positions can be leveraged across multiple segments, inherently impacting both consumers and competitors in the digital economy.