I would be more interested in seeing the other thing - that increase in productivity results in higher salary.
(It is taken from granted, but it does not seem to be the case in service-oriented jobs. More productivity means less people are needed to do the job, and while customers are happier at falling prices, it does not mean there is any benefit for the employees - except for lay offs.)
Applying a vastly simplified model, every job has a salary range possible:
From the company's side: At most the amount of money you make the company, and at most the cost of hiring a replacement who could do the same job equally well.
From your side: At least the second-best job offer you've received.
Raising productivity is often a prerequisite for raising salaries - but you also need a tough hiring market, if you want the business to give the money to the workers instead of the bosses, investors or customers.
(It is taken from granted, but it does not seem to be the case in service-oriented jobs. More productivity means less people are needed to do the job, and while customers are happier at falling prices, it does not mean there is any benefit for the employees - except for lay offs.)