Much has changed since Baron and Kenny's (1986) classic paper: let us learn what Kenny's (2012) contemporary mediation analysis prescribes

The procedure set for mediation analysis in the Baron and Kenny’s (1986) classical research article did not go without criticism (MacKinnon and Fairchild, 2009; Hayes, 2009; Bullock, Green, & Ha, 2010; Zhao, Lynch and Chen, 2010), and thanks to those critics, that Kenny (2012) had to bring a number of modifications and improvements through his today’s contemporary mediation analytic procedure. This paper presents a comparison of what Baron and Kenny (1986) had originally proposed, and what Kenny (2012) has now suggested after incorporating critics’ concerns. For this purpose, the two approaches of mediation analysis have been practically applied on an organizational justice - trust in supervisor - employees’ job satisfaction case, wherein variable ‘trust in supervisor’ was used to mediate between various facets of organization justice and employees’ job satisfaction. Whereas the classic approach required the estimation of the four paths (c, a, b & c’), through four steps and running three regression equations and testing for their statistical significance; the contemporary mediation analysis has shortened the paths from four to three (a, b & c’), requiring taking only two steps (Steps 2 and 3), and running two regression equations, declaring the first equation as unnecessary. The classic approach required that path b needs to become statistically significant and path c’ insignificant in step 3 & 4 for a complete mediation; contemporary approach asks for adding c’ with ab for determining total effect c, and then decomposing c in to direct effect (c’/c) and indirect or mediation effect (ab/c). Whereas classic approach aimed at solving for full or partial mediation in abstract form, the contemporary approach has the edge over the classic, in quantifying the mediation effect (ab). In case of our solved example, classic approach could only help to indicate that ‘trust-in-supervisor variable is partially mediating’, while in case of contemporary approach, mediation effect of this variable for INJ facet of organizational justice was not only quantified (17.36%) and tested for its non-zero effect, but zero-effect of other two facets, DJ and IJ, were also differentiated.