This article (wig wiggle: The Browser) discusses various ways the Chinese judicial system differs from Western courts.  One significant difference is summarized by Columbia Law Professor Benjamin Liebman:

Yet China’s courts are as deeply committed to populism as they are to professionalism. If Chinese judges decide to ignore a law in order to preserve thousands of jobs, they aren’t violating a sacred legal precept. “They’re supposed to take into account popular interests,” Liebman explains.

The article presents this in a way that presupposes that it will be obvious to us that this is a bad approach to judging.  Indeed, public debate in the US about “judicial philosophy” also takes for granted that judges should base their opinions on the law, and not on popular opinion. But why is this so obvious?  Why shouldn’t the job of a judge be to decide on a case-by-case basis what is in the public interest?

Put aside the obvious reasons.  Popular opinion may be hard to read and political voice may not be equally allocated.  Judges are administering justice, especially for those without political voice.  Popular opinion may be short-sighted and judges are expected to be immune to short-run pressures and make decisions with better long-run consequences.

But even in cases where it is transparent and uncontroversial what the public interest is and there is no short-run/long-run trade-off, judges still should not decide cases on that basis alone.  In fact, one of the most important functions of the court is to act against the public interest.  Because incentives to make good decisions typically require that we expect a bad outcome if instead we make bad decisions.  And ex post that bad outcome is typically not in the public interest.  A court that is committed to uphold the law and act against the public interest ex post advances the public interest ex ante.