Can the same person play both the Product Owner role and the Scrum Master role?

Does the Scrum Guide expressly preclude this arrangement when implementing the Scrum Framework?

What are your own thoughts about the circumstances under which these roles should not be combined in the same person?

Can the same person play both the Product Owner role and the Scrum Master role? 

@Monir Khan, The short answer is Yes.

The Scrum Guide does not say that this can't be, however, what needs to be understood is, can one person truly bring the right amount of transparency required for each role? Can they demonstrate the Scrum Values and not be in a state of conflict while playing both roles?

If those trade-offs are understood, then a person may play both roles.

Hope this helps.

Thank you both - Ian and Steve.

Yes, there are certainly some concerns with conflict of interest by playing both the roles by the same person. 

@Ian - No, it's not forbidden by the Scrum Guide (there's no reference to it) but it sure can introduce lof of conflicts of interests.and should not be recommended due to all the reasons Steve outlined above.   Thanks.

So the bottom line - it is not forbidden as per the Scrum Guide but certainly not recommended to avoid conflit of interest.

It's important to also consider why this question is asked.

For instance, I have worked in places where the emphasis is on utilization, with the assumption that a busy employee is an effective one; and so there is a temptation to appoint an existing employee to work as a Scrum Master, whilst they continue in their previous function. This can also be a symptom of an organization that doesn't see the value in having a Scrum Master, and is just paying lip-service to Scrum.

The result can be a flaccid implementation of Scrum, that doesn't result in meaningful change from what went before, with a Scrum Master who is too busy with their "main job" to challenge the organization, or to step in when things are going wrong.

Having a dedicated Scrum Master — particularly one who has enough free time to involve themself when it's helpful — will often result in more value being delivered, than just having a team full of busy people.

Thank you, Simon, for sharing your experience.

Corporations, all sizes try to save money any way they can. this is just how it is and most of the time it is not effective.

Plus a lot of large enterprises follow old ways of doing stuff (predictive/waterfall approach). I hear there are discussions about agile in the enterprise, management/execs talk about it, I think they do it as they think it is cool, a new paradigm and that's it really. 

Corporations, all sizes try to save money any way they can. this is just how it is and most of the time it is not effective.

Can savings in compensation justify the potential risk of lack of transparency, focus, and possible conflict?

In addition, the power balance shift also tends to introduce a hierarchy in a different way. Is that the motive of the organization or the PO? If it is then I would call it an anti-pattern. 

"Can savings in compensation justify the potential risk of lack of transparency, focus, and possible conflict?"

@ Aditya Vaze maybe not but this is the reality that we have to navigate through no matter how strong we make the agile/scrum points.