Standard Error has awarded the Best Paper Prize at the 2026 CINCH Economics of Mental Health workshop to Alden Cheng (University of Illinois, Urbana-Champaign) and Martin B. Hackmann (UCLA) for their paper “Patient peer effects: Evidence from nursing home room assignments.” 

 In addition to selecting and awarding the Best Paper Prize, Standard Error joined the B. Braun Foundation and SHARE France as sponsors of this year’s edition of the workshop, hosted in Paris on June 22–23 by CINCH of the University Duisburg-Essen and Paris Dauphine University. 

The prize—the second that Standard Error has awarded in this workshop series—recognizes the authors’ outstanding empirical work and the direct applicability of their findings for improving patients’ health outcomes. 

Health economists Cheng and Hackmann skillfully use the causal inference toolkit of economics to reveal another input in patients’ outcomes: their peers.  

Poor quality of care in nursing homes costs lives and is a matter of serious concern across aging societies worldwide. Health economists Cheng and Hackmann skillfully use the causal inference toolkit of economics to reveal another input in patients’ outcomes: their peers. Indeed, they find that nursing home patients’ roommates can affect their mortality to a degree comparable to differences in provider quality.

How peers help produce patients’ health outcomes

The authors’ research design leverages nursing home patients’ quasi-random assignment to rooms on the basis of room availability to examine the mortality impacts of assignment to a roommate with Alzheimer’s disease (AD) or Alzheimer’s disease–related dementias (ADRD). Their sample covers 2.5 million stays in 7,200 US nursing homes from 2000 to 2010. 

 They find effects of remarkable statistical and economic significance: Assignment to a roommate with AD/ADRD increases 90-day mortality from its baseline level for patients assigned no roommate by 7%—over 1 percentage point. This effect on patients’ mortality is the same as that of receiving care from a provider with half of a standard deviation poorer quality.

peers make a key contribution to health outcomes in nursing homes by monitoring and giving behavioral support to their cognitively impaired roommates  

The effects are driven by patients who themselves have AD/ADRD, who—when assigned a cognitively well roommate—show mortality declines of 3.4 percentage points in comparison to those assigned a roommate also affected by AD/ADRD and a decline of 1.4 percentage points in comparison to AD/ADRD patients assigned no roommate at all. Patients without AD/ADRD, in contrast, show no mortality effects from sharing a room with a peer affected by AD/ADRD. 

The authors take these differences as evidence that peers make a key contribution to health outcomes in nursing homes by monitoring and giving behavioral support to their cognitively impaired roommates. An implication is that strategically assigning patients to roommates who can support their care—instead of matching roommates on their cognitive status, the prevailing policy in many care facilities—can extend lives. The authors formulate a rule to minimize mortality through assignment of patients with mixed cognitive status as roommates and estimate that it could reduce 90-day mortality by 0.6 percentage points. 

About the Standard Error Best Paper Prize

Our Best Paper Prize aims to bring innovative, policy-relevant scholarship by early career researchers to broader academic and public attention. Prizewinners receive a round of expert editing and consulting on a work in progress of their choice. 

 Standard Error also selected the best paper at last year’s edition of the CINCH Economics of Mental Health Workshop. That prize went to Ashish K. Sedai of the University of Texas at Arlington and coauthors at the Asian Development Bank Institute and Indian Statistical Institute for their research on an intervention to support adolescents’ mental health by fostering cooperation between their parents.