Halo effect is basically a cognitive bias. In this bias, the perception
of a particular trait is influence by the former traits. This phrase is
normally used in Human resource management in the area of recruitment.
On the other hand, the zero effect theory concerns the environment around the company. When a company adopts the zero effect theory, it promises that it would drive the defects such as landfill waste, carbon emissions and energy used to zero. The motto of such company is Reduce, Reuse and Recycle.