Job applicants often face extensive, unpaid interview processes, including numerous interviews, additional tasks and presentations, and sometimes don’t get the job, but then find that the org has used their ideas without asking for permission. This is unfair, especially to those in financial need at the beginning of their career. 

A reform is necessary.  

Trial projects are likely here to stay. They offer an opportunity for employers to assess whether a candidate is a good fit for their type of work and their working culture. Also, they enable a candidate to gauge whether they want to work for the company. 

To promote equity, candidates should be compensated for their time. While trial projects are useful for mutual assessment, they should be paid engagements.

I would like to research the topic and prepare the mathematical models to show that is mutually beneficial.

I have 5 hypotheses. 

1. Paying for job interviews is positively correlated with expected salary 

2. Paying for interviews is positively correlated with showing up as more qualified candidates 

3. Paying for interviews is positively related to the number of candidates 

4. Paying to interview is positively correlated with satisfaction with the interview process 

5. Paying for a call is positively correlated with the company's image in the eyes of customers 

Has anyone participated during the paid trials / paid interviews in the companies? Does any know what companies doing the paid trials? Do you have direct contact with people who were responsible for the process?