The corporate boards of public and private companies headquartered in the United States have twice as many Republicans as Democrats, a new study published by Harvard Business Review found.

According to the research, these boards are “50% Republicans, 24% Democrats, and 26% Independents, while the American public, according to Gallup, is 28% Republicans, 31% Democrats, and 39% Independents.”

Harvard found women directors are more ideologically diverse than their male counterparts, with Republicans and Democrats split about evenly.

“By comparison, male directors are more than twice as likely to identify as Republicans than Democrats,” the study showed.

Age and education didn’t appear to be notable factors influencing the partisanship of board members, but different industries did make a difference.

“Boards of companies operating in the consumer discretionary industry have a disproportionately high representation of Democrats,” the study found, “while boards operating in the industrials and energy and utilities industries skew more Republican. The proportion of Democrat and Republican directors does not substantially differ between public and private firms.”

The data also showed some contemporary political divisions are playing out in boardrooms:

“Democrats are less pessimistic about the economy: 10% of Democrats expect a global economic slowdown in the next three years, compared to 18% of Republicans. Democrats care more about economic justice, environmental sustainability, and equal rights for women. Republicans care more about corporate tax rates, the national budget deficit, and regulation.”

The study did have surprises, though. Republican directors said the compensation level of the CEO of their company is “too high,” perhaps suggesting that at least a tiny bit of the GOP’s ascendant populism has found its way to the corporate suites.

Follow Graham on Twitter