Limiting job applications in an online labor market: by John Horton and Shoshana Vasserman

 Here's an experiment that involved limiting the number of applications to particular jobs in an online labor market, in which many applicants are likely close substitutes.

Job-Seekers Send Too Many Applications: Experimental Evidence and a Partial Solution by John J. Horton and Shoshana Vasserman

Abstract: As job-seekers internalize neither the full benefits or costs of their application decisions, job openings do not necessarily obtain the socially efficient number of applications. Using a field experiment conducted in an online labor market, we find that some job openings receive far too many applications, but that a simple intervention can improve the situation. A treated group of job openings faced a soft cap on applicant counts. However, employers could easily opt out by literally clicking a single button. This tiny imposed cost on the demand side had large effects on the supply side, reducing the number of applicants to treated jobs by 11%—with even larger reductions in jobs where additional applicants were likely to be inframarginal. This reduction in applicant counts had no discernible effect on the probability a hire was made, or in the quality of the subsequent match. This kind of intervention is easy to implement by any online marketplace or job board and has attractive properties, saving job-seekers effort while still allowing employers with high marginal returns to more applicants to get them.

"In this paper, we describe an experiment conducted in an online labor market that influenced the size of applicant pools faced by employers.1 This was done by imposing a soft cap on the number of applicants that a job opening could receive, as well as limiting the duration of the window of time during which applications could be received: when a job opening received 50 applicants—or when 120 hours (5 days) had passed—no more applicants could apply unless the employer explicitly asked for more applicants. The intent of the intervention was to prevent job-seekers from applying to jobs where their application was likely to either be ignored or simply displace some other applicant, without preventing employers with high marginal returns to more applicants from obtaining them.

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There is no evidence that better or worse matches were made in the treatment group, as measured by the feedback given by the employer at the end of the contract or in hours-worked. If anything, employer satisfaction rose slightly in the treatment.

The lack of effects on hiring or match quality is seemingly surprising, but likely reflects the fact that price competition among workers “prices in” vertical differences among workers, leaving firms close to indifferent over applicants, as in Romer (1992). Because of this indifference, substitution among applicants is not very costly to employers.

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"only about 7% of employers requested more applicants by pushing the button.

"The treatment intervention likely saved job-seekers substantial time—more so than the percentage changes in job post applicant counts would seemingly imply. To see why the treatment has out-sized effects on job seekers, note that although relatively few job openings were affected by the 50 applicant cap (about 10%), these job openings are disproportionately important to job-seekers, as they attracted 43% of applications. This difference simply reflects the fact that a randomly selected application is more likely to be sent to a job with a high applicant count.

Hiring America's soldiers

The veterans' publication Task and Purpose has the story:
The Recruiters: Searching For The Next Generation Of Warfighters In A Divided America  By ADAM LINEHAN 

"Since the draft was ended in 1973, recruiting has become one of the most important jobs in the military. For the Army, it’s imperative. While the Marine Corps prides itself on being lean, mean, and agile, and the Navy and Air Force increasingly rely on unmanned vehicles and long-range munitions, the Army’s greatest contribution to the battlefield is, and always has been, people. Roughly 70% of the nearly 7,000 U.S. troops killed so far in Iraq and Afghanistan were Army soldiers. Most were recruited through centers like the one in East Orange.

"Headquartered in Fort Knox, Kentucky, U.S. Army Recruiting Command, or USAREC, manages the recruiting mission for the service’s active-duty and reserve components. It is a massive, ever-evolving operation involving approximately 12,500 military and civilian personnel spread across 1,400 recruiting centers in the United States and abroad, including in Europe and Guam. Roughly $4.6 billion of the Army’s $33.8 billion budget for fiscal year 2017 was allotted for recruiting and training new soldiers; $424 million of that was spent on bonuses alone. The Army also poured more than $289 million into television, radio, digital media, direct mail, and sports-related advertising campaigns. A lot of blood, sweat, and tears goes into keeping the ranks filled with qualified volunteers. The recruiting machine never stops.

"The biggest factor in recruiting success is the health of the economy. Typically, when the unemployment rate goes up, so does the number of Americans wanting to join the military. Nonetheless, the more economically stressed, socioeconomic classes tend to be underrepresented in the armed forces. Although people in low-income neighborhoods are generally more inclined than their wealthier compatriots to enlist, fewer and fewer have the qualifications to serve. Rising standards are part of the reason. But so are a host of societal problems that tend to hit disenfranchised populations especially hard, such as increasing obesity rates and a public education system that disadvantages low-income zip codes.

"Currently, only about 29% of Americans between the ages of 17–24 are eligible to serve. Disqualifiers include lack of a high-school diploma or GED; tattoos on the hand, face, or neck; a wide range of physical and mental-health problems; a history of illegal drug use, and a criminal record.
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"Bryant believes the Army could keep its ranks filled by focusing on a handful of states, most of them south of the Mason-Dixon line, while paying extra attention to communities within those states that have formed around military installations. Current trends support this view: Of the newest crop of Army recruits, half came from just seven states; 79% had relatives who served. The military has become increasingly — some would even add dangerously — insular since the advent of the all-volunteer force. As the journalist Thomas E. Ricks noted in a 1997 article for The Atlantic titled The Widening Gap Between Military and Society, this trend toward homogeneity was likely accelerated by the closing of dozens of bases and installations following the end of the Cold War, which significantly reduced the military’s footprint in the West and Northeast. 

“You can kind of draw a smiley face from North Carolina around the southern United States halfway up California, and that’s where the majority of [military] post, camps, and stations are,” Snow said. “Youth who have more interaction with those in uniform tend to [be more likely to enlist].” Could the Army shutter its recruiting centers in the Northeast and still meet its quotas? Snow suspects it could. “But then we’re getting away from the very principles that we pride ourselves on, and that’s that we are a microcosm of society,” he added.