How sales, profit margins, and buyback have boosted earnings per share growth each year since 1967

Investors want the companies they invest in to deliver earnings growth.

Earnings growth is largely driven by sales growth and profit margin expansion.

For investors who are concerned about earnings on a per-share basis, EPS growth is further driven by share buybacks. Indeed, in the most recent quarter, there'd actually be no EPS growth without buybacks.

Buybacks are controversial because the EPS growth they produce is the product of financial engineering, not demand for goods or operational efficiencies.

"Buybacks are an important part of the earnings payout and a significant driver of total shareholder return and EPS growth in a slow sales world," Deutsche Bank's David Bianco writes. "S&P trailing 4qtr net buybacks are $425bn, close to 2007 peak levels. We think buybacks will continue at their current pace or contract slightly in 2016."

So, just how much of an impact have buybacks had in history?

"Since 1Q12, buybacks have contributed 1.4% to S&P EPS growth on average or ~20% of average EPS growth of 6.2%," Bianco observed.

In a new presentation to clients, Bianco exhibited this chart breaking down the drivers of earnings per share growth. As you can see, buybacks (and share offerings) historically haven't been the big driver of EPS growth.