Basically this is the factor of productivity of workers with respect to pay,light, humidity and rest breaks. It is eventual that all the factors have worked in different time and with different combinations. With reference to Elton Mayo, any productivity model should be a factor in intangable attributes like human behaviour.
The Yerkes-Dockson law depicts and law of Dimnishing Marginal utility, when motivation does increases productivity to certain point, any more motivation would not be effective due to satururation of utility.
The Pygmalion Effect: it is self-fullfilling prophecy, building trust on others and to make them to perform accordingly.
The Placebo Effect: Creating beleif among the people by ineffective treatment, by which individual believes that it will work.
My Intrepretations
In recent times, factors which are supported by external environment (Salary, AC room, Personalized laptops, Salary hike every quater, Bonus, Special offers) works, but it should be bounded by individual's traits. Traits are characteristics which support individual to retain the temporary motivation or thrust by external environment. Traits include loyalty, dedication and so on. If an individual built with all these traits then above theories work and firms should focus on inculcating such traits within their employees.
