The key finding, embodied in the sentences immediately before the one you quoted, is that more research is needed because there is not enough firm data to form

The key finding, embodied in the sentences immediately before the one you quoted, is that more research is needed because there is not enough firm data to form a consensus. I suspect the lack of consensus regarding gambling mechanics in games is along the lines of the former 'lack of consensus' surrounding the causal link between smoking and lung disease or the current 'lack of consensus' connecting CO2 emissions and global warming, however. Namely, a manufactured dispute created to defend the indefensible.