Huselid, Mark. "The Impact of Human Resource Management Practices on Turnover, Productivity, and Financial Performance." Academy of Management Journal, 1995.
(According to the author's website (here) this is "the most frequently cited article in the 50+ year history of the Academy of Management Journal.")
From the author's conclusion: "Prior work in both the academic and popular press has argued that the use of High Performance Work Practices will be reflected in better firm per- formance. This study provides broad evidence in support of these assertions. Across a wide range of industries and firm sizes, I found considerable support for the hypothesis that investments in such practices are as- sociated with lower employee turnover and greater productivity and corporate financial performance. That my results were consistent across diverse measures of firm performance and corrections for selectivity and simultaneity biases lends considerable confidence to these conclusions.
"The magnitude of the returns for investments in High Performance Work Practices is substantial. A one-standard-deviation increase in such practices is associated with a relative 7.05 percent decrease in turnover and, on a per employee basis, $27,044 more in sales and $18,641 and $3,814 more in market value and profits, respectively. These internally consistent and economically and statistically significant values suggest that firms can indeed obtain substantial financial benefits from investing in the practices studied here."