When we asked owners in our operator survey what they wanted, nobody wrote in asking for more applicants.

They wrote "more trustworthy, dependable coworkers," "more quality employees," and "better people managing skills."

Most owners file that under hiring or under retention and go fix one. A seat you can't fill feels like a recruiting problem. A seat that keeps emptying feels like a retention problem. The research points somewhere else: they're one loop, and the people you keep decide who you can hire next.

The best evidence comes from trucking, not tree care. A team of economists studied personnel records from a very large U.S. trucking firm, plus call centers and a large tech company, and published the work in the Quarterly Journal of Economics in 2015. Long-haul driving is physical, safety-critical, high-turnover work, about as close to a tree crew as well-measured data gets.

Referred drivers quit less than drivers hired off the street. In the 2013 working-paper version of the same study, what mattered was who made the referral. Hires referred by the firm's above-median drivers were the most profitable group. Hires referred by below-median drivers made the company less money than the average driver who walked in cold. And when the referring driver had an accident at some point, the person he referred was 14% more likely to have one too.

People refer people like themselves, work habits included. Your most dependable climber knows other dependable climbers. The guy who's late twice a week knows guys who are late twice a week, and a bring-a-buddy bonus flyer in the shop asks both of them to recruit.

So when a top hand quits, you lose his work plus the people he would have brought in.

Ask your two or three best people for referrals, one at a time.

Pull each one aside, away from the tailgate meeting, and ask: "Who is the best hand you've ever worked next to who doesn't work here?" Get a name and a phone number.

If you pay a referral bonus, pay it on their referrals, or at least move their names to the front of the line. The trucking study's authors suggest the same thing in their 2013 working paper: firms could "award the greatest weight in their hiring process to those referred by the best workers." Tie the payout to the new hire meeting your standard. A field experiment in Kolkata, India (American Economic Review, 2012) found that paying people based on how their referral performed made them more likely to refer coworkers and less likely to refer relatives. If you know by day 30 whether a hand meets your bar, pay at 30. The calendar matters less than tying the money to your standard instead of to a warm body.

A referral bonus helps you pick better people. Keeping them is a separate job. The trucking study and a 2012 Federal Reserve Bank of New York report on one large U.S. company both found that making the bonus depend on the new hire staying a set time (30 days to six months in these studies) didn't change when referred workers quit. A bad foreman or thin pay will still empty the seat. And keep a public job posting open alongside the referrals. The EEOC warns that leaning on word-of-mouth recruiting when your crew is mostly one race, ethnicity, or nationality may violate the law if nearly all your new hires end up from that same group.

Action Steps:

The crew you keep is already your hiring channel, whether you run it on purpose or not. The people you hold onto decide who walks in next. Last week was the case for raising prices before adding a crew. This is the other half: when you do go to hire, your best people are the shortest line to someone worth keeping.

If you run the ask this week, reply and tell me whether a name came back. You don't need to send the name itself. I'll help you figure out the next step.

Here's to a crew worth cloning.

- Jacob Hastings

The Backcut