A happy worker is a productive worker, common sense says, but despite some studies that claim to reveal this correlation, over 70 years of research has not yet proved the axiom true.

Little wonder: It’s a tough thing to measure. These are subjective concepts, after all. What it means for an employee to be “happy” and “productive” changes from study to study and organization to organization. No single definition could ever fit all businesses.

We sat down with China Gorman, HR consultant and former SHRM chief, to discuss why entrepreneurs, when picking perks for employees, often choose the “bread and circuses” model popularized by Silicon Valley technology firms and the mainstream media.

Tobacco use is the scourge of workplaces everywhere, just ask any smoker who works in an office setting. Businesses ban lighting up in buildings, penalize users through their wellness programs, and relegate smokers to taking their breaks in out-of-sight crannies near alleyway dumpsters.

Health care is expensive for businesses. Those who go through insurance companies must deal with rising premiums and growing uncertainty. And the ones that self-fund health benefits are only so insulated from increasing costs. In the search to buttress the bottom line, corporate wellness programs are doing a good job of improving worker health so that costs are eliminated before they occur.