Search Engine Bias Is Necessary and Desirable
Before trying to solve the "problem" of search engine bias, we should be clear how search engine bias creates a problem that requires correction. From my perspective, search engine bias is the unavoidable consequence of search engines exercising editorial control over their databases. Like any other media company, search engines simply cannot passively and neutrally redistribute third-party content (in this case, web publisher content). If a search engine doesn’t attempt to organize web content, its system quickly and inevitably will be overtaken by spammers, fraudsters, and malcontents.  At that point, the search engine become worthless to searchers.
Instead, searchers (like other media consumers) expect search engines to create order from the information glut. To prevent anarchy and preserve credibility, search engines unavoidably must exercise some editorial control over their systems. In turn, this editorial control necessarily will create some bias.
Fortunately, market forces limit the scope of search engine bias. 
First, searchers have high expectations for search engines: They expect search engines to read their minds  and infer their intent based solely on a small number of search keywords.  Search engines that disappoint (either by failing to deliver relevant results, or by burying relevant results under too many unhelpful results) are held accountable by fickle searchers.  There are multiple search engines available to searchers,  and few barriers to switching between them. 
As a result, searchers will shop around if they don’t get the results they want,  and this competitive pressure constrains search engine bias. If a search engine’s bias degrades the relevancy of search results, searchers will explore alternatives—and that’s true even if the searchers don’t realize that the results are biased. Meanwhile, search engine proliferation means that niche search engines can segment the market and cater to underserved minority interests.  Admittedly, these market forces are incomplete—searchers may never consider what results they’re not seeing—but such forces are powerful nonetheless.
In contrast, it’s difficult to imagine how regulatory intervention will improve the situation. First, regulatory solutions become a vehicle for normative views about what searchers should see—or should want to see.  How should we select among these normative views? What makes one bias better than another?
Second, regulatory intervention that promotes some search results over others doesn’t ensure that searchers will find the promoted search results useful. Determining relevancy based on very limited data (such as decontextualized keywords) is a challenging process, and search engines struggle with this challenge daily. Due to the complexity of the relevancy-matching process, government regulation rarely can do better than market forces at delivering results that searchers find relevant. As a result, searchers likely will find some of the promoted results irrelevant.
The clutter of unhelpful result may hinder searchers’ ability to satisfy their search objectives, undermining the searchers’ confidence in search engines’ mind-reading abilities.  In this case, regulatory intervention could counterproductively degrade the value of search engines to searchers. Whatever the adverse consequences of search engine bias, the consequences of regulatory correction are probably worse.