For decades, the number of women studying economics seemed to be increasing, easing the persistent scarcity of professional female economists in the United States. But that progress has stalled.

New data indicates that the share of women studying the subject in America’s universities has flatlined and the pool of prospective female economists may even be shrinking.

That pattern would be disturbing in any academic field but because economics has an outsize influence on public policy, it means that many important debates are likely to be dominated by men’s voices for years to come.

At virtually every level of training and every professional rank within economics, women are a minority. And women are less likely than men to progress at each successive step along the career path, so this imbalance is more lopsided at senior levels. This situation has been called a “leaky pipeline” but as long as increasing numbers of women entered that pipeline, the number of female economists kept rising.