A new study by Carver Edison shows that over the last five years, public companies with employee stock purchase plans (ESPPs) had a return on equity of nearly 12% per year, compared to 7% in companies without these plans. They had operating margins of 9.5%, compared to 8.2% for non-ESPP companies, and they had four times the annual sales growth (4% to 1%). Almost half the S&P 500 and 40% of the Russell 3000 offer these plans. The study was based on market-weighted indices of ESPP and non-ESPP companies. It is not possible to tell whether companies that offer these plans tend to be better performers to begin with or whether there is a causal relationship with ESPPs.

Summarizing the research, Carver Edison's founder Aaron Shapiro writes, "While ESPPs provide wealth building opportunities for employees, data shows that their presence as part of a company’s benefits package is also generally accretive for shareholders, especially in the technology, healthcare, and financial services sectors."