Votes on remuneration by the shareholders' meeting (Say on Pay). It is not obligatory but in many studies it is argued that the behavior of shareholders could influence the remuneration policies.
SOP generally comes with a complete reform of the regulation on CEO pay. I would guess it has an effect. Generally, I've seen papers recently on how activism affects Corporate Governance even when it (Activism) fails. I guess there is US research on the effects of SOP.
as i know, common law countries have strong enforcement therefore activism might play a role but in civil law countries the enforcement of corporate governance is quite low and thus activism may not play a role
In France Say On Pay has little influence till now. In this civil law counrtry CEO's compensations are much more related to the size of the company, and not really to its profits and only a little to shareholders activism..