Voters in a primary are a bit like members of a hiring committee. They have a batch of eager candidates and must choose one to represent their party and–they hope–hold the office.

I have served on dozens of hiring committees, including some for nonprofit CEOs and senior university administrators. Head-hunters give consistent advice about how to assess candidates. They advise committees not to ask how a candidate will or would address issues in the future. Candidates don’t really know, because their strategies will depend on the details of the issue and the other stakeholders’ actions. They almost inevitably give platitudinous responses: “I will bring people together, build consensus, and then move decisively.” “I will identify the ineffective programs and phase them out.” Such responses have zero informational and predictive value. Instead, committees should ask candidates how they actually addressed challenges in their previous work, and what they learned from that experience. This is more informative.

I don’t think that advice applies to voters in legislative elections. A legislator faces decisions about whether to vote yea or nay on bills. Newly elected legislators–back-benchers–do little else than vote yea or nay. It makes sense to ask legislative candidates (especially newcomers) how they would vote.

I realize that voters around the world are cynical about politicians’ promises. But I think cynicism should be reserved for their very general rhetoric about outcomes. “I will bring the country together” or “I will generate 5% growth” — these are promises waiting to be broken. (If they come to pass, it’s mostly good luck.) On the other hand, when candidates say, “I will support HR 1234,” that is quite predictive. It’s good to ask them how they will vote.

But presidents are more like CEOs than legislators. To be sure, they face decisions about whether to sign or veto bills, but those are rarely their decisive actions. Most of their impact results from hiring, firing, and guiding subordinates and jawboning all kinds of independent actors: 535 members of Congress, foreign heads of state, civil society actors and corporate leaders. (They also have the bully pulpit to address the nation, but the impact of that is somewhat overrated.)

We’d like to know how well they’ll do in those conversations and what their (precise) objectives will be. But what they say how they will deal with other people has limited value. It’s currently fashionable to place Democratic candidates on a scale from accommodating to tough, where the question is how they will handle their relationship with Republicans. I don’t think how they present themselves on the campaign trail predicts that very well at all.

Candidates should publish policy briefs, and we should read them. The main reason is that a campaign is a precious opportunity for a national debate about issues, influencing citizens’ knowledge and values. But policy briefs are not very informative about a candidate’s actual performance as president.

A brief may tell you something about the candidate’s goals and values. A Democratic candidate who says “Medicaid for all,” is conveying more progressive ideals that a candidate who asks, “How will we pay for that?” But an actual Democratic president will not choose between those two policy positions. She or he will: (1) choose one or two issues to emphasize at key moments, (2) deal with members of Congress across the spectrum about those issues and the many issues that arise for other reasons; and (3) decide whether to sign or veto the actual bills that emerge from Congress–if any do. Asking candidates how they will perform those tasks is not terribly informative, because the question yields platitudes of the form, “I will bring people together and move forward together” or “I will rally the troops and drive change through.” (Those sound different, but neither describes what they will actually do.)

The 2020 Democratic Primary has generated an especially large number of interesting policy proposals. The Warren campaign, in particular, has made a meta-issue of having detailed policy briefs. (“I have a plan for that.”) I like the message that Warren is detail-oriented and interested in policy, a major contrast to the incumbent and probably predictive of how she would govern. I like the ethic of presenting specific ideas to the voters: it takes people seriously as thinkers. I also think the policy debate among candidates may have some influence on other actors–Members of Congress, interest groups, and the public–which is beneficial. But I would still take the headhunters’ advice and focus more on how candidates have actually dealt with challenges than on what they say they would do if they were president.