People don’t tend to publish negative results. What problems does this lead to?

The problem with researchers not publishing negative results is that other researchers may repeat their experiments or conduct similar ones unknowingly and waste time finding that same negative result. This may happen often when there are many research groups or labs that are studying the same phenomenon or area. Hypotheses and theories in that area of research may be shared between these labs which could lead to many people conducting similar experiments. If one group were to publish their negative results, that would save other people from wasting time conducting those experiments. If people published their negative results more often, research on a large scale would be much more efficient and could move more quickly.