Select Publications

Singh, M. (2021). Heuristics in the delivery room. Science, 374(6565), 324-329.


Clinical decisions made in the delivery setting are often made under high pressure, great uncertainty, and have serious consequences for mother and baby. Theories of decision-making suggest that individuals in such settings may resort to using “heuristics”, or simplified decision-rules, to aid complex decision-making. This study investigates whether physicians’ delivery-mode decisions (i.e., when to perform a vaginal vs. a cesarean) are influenced by such a heuristic. Electronic health record data spanning 86,000 deliveries suggests that, if the prior patient had complications in one delivery-mode, the physician will be more likely to switch to the other -- and likely inappropriate -- delivery-mode on the subsequent patient, regardless of patient indication. There is evidence that this heuristic has small, suboptimal effects on patient health.

Results as a limerick

A patient has a bad reaction,

To the Doc’s deep dissatisfaction, 

Feeling unfit,

Doc cries out, "Oh sh*t!"

And switches her medical plan of action.

Press: Random Acts of Medicine, New York Times UpshotLA Times, The Conversation, Quartz, Reuters Health, Technology Networks, Yahoo Finance, MedicalXpress, American Council on Science and Health, NewsWise, PressReleasePoint, The Deccan Her- ald, DevDiscourse, Haaretz, Arizona Daily Star, Dispatch Argus, The Buffalo News, Lincoln Journal Star, Bozeman Daily Chronicle, Yahoo News, Fairfield Citizen, Seattle Post-Intelligencer, Medical Xpress, Pourquoi Docteur, DNYUZ, Mirage News, The Medical News, KRQE, Latestly, Foreign Affairs New Zealand, St. Louis Post-Dispatch, GoSkagit, Entrepreneur, Bismarck Tribune, KULR, The Darien Times, Shelton Herald, New Canaan Advertiser, San Antonio Express News, Idaho Press, La Vanguardia

Click HERE for an ungated link to the paper

Working Papers

Rationing by Race (with Atheendar Venkataramani)

(Previously circulated under the title "Capacity Strain and Racial Disparities in Hospital Mortality ", NBER WP 30380)


A growing literature has documented racial disparities in health care. We argue that racial disparities may be magnified when hospitals operate at capacity, when behavioral and structural conditions associated with poor patient outcomes – e.g., limited provider cognitive bandwidth or reliance on biased care algorithms – are aggravated. Using detailed, time-stamped electronic health record data from two large hospitals, we document that in-hospital mortality increased more for Black patients than for White patients when hospitals approached capacity. We estimate that 8.5% of Black patient deaths were capacity-driven and thus avoidable. We then investigate the extent to which differential care inputs explain our findings. While strain exacerbated wait times similarly for Black and White patients, Black patients both waited the longest at high strain and faced greater mortality consequences from prolonged wait times. Finally, the largest racial disparities in mortality were among women and uninsured patients, highlighting biases in provider behavior and hospital processes as key mechanisms driving our results.

Results as a limerick

On clinical capacity does care depend 

whether or not providers intend, 

Hospitals get busy,

all systems a-tizzy,

with disparities emerging in the end.

Do Physicians Improve More from Positive or Negative Feedback? (with Jacob Zureich) (Second-round revisions at Management Science)


We use clinical data on over 240,000 surgeries and several quasi-experimental methods to examine how physicians respond to the surprise release of a quality "report card". Such feedback interventions are commonly used to encourage physicians to improve performance, yet show limited evidence of success. Our results show that these limited effects mask heterogeneous behavioral responses to feedback valence. In particular, physicians improve more from positive feedback than from negative feedback, with negative feedback even reducing performance for a non-trivial share of physicians. Experiments with laypersons replicate these results and show that struggles with negative feedback can be mitigated by giving incentives directly tied to improvement and by adding qualitative information that helps individuals interpret past performance. These results are consistent with behavioral models that suggest cognitive and emotional difficulties limit how well individuals use negative feedback. Thus, feedback interventions in healthcare should be carefully designed to mitigate counterproductive behavioral responses.

Results as a limerick

Are report cards a fad?

Or could they help just a tad?

We find feedback is tricky,

‘cuz priors are sticky

And the good helps more than the bad.

How Power Shapes Behavior: Evidence from Physicians (with Steve Schwab) (Under Review)


Power, defined as the asymmetric control of valued resources, affects most human interactions. Yet there is little observational evidence on how power affects behavior and resource allocation. We examine this question using the power differential in the doctor-patient encounter: while it favors the physician in the clinical setting, powerful patients may be able to reduce this asymmetry and so influence physician behavior. We exploit the quasi-exogenous assignment of 1.5 million patients to physicians in US military emergency departments, using the difference in their military ranks to measure their power differential. We find that power confers nontrivial advantage to its possessor: “high-power” patients (those who outrank their physician) receive greater physician effort and have better outcomes than equivalently-ranked “low-power” patients. We document other suggestive results: (i) within-physician effort is higher for patients recently promoted than those about to be promoted, (ii) low-power patients suffer when their physician concurrently cares for a high-power patient, and (iii) rank-based power dynamics vary predictably by doctor-patient concordance on race and sex. While power-driven variation in behavior is often undesirable, it is especially concerning in healthcare where it can harm society's most vulnerable patients.

Results as a limerick

Is power too beckoning a call?

Since doctors are human after all,

We took the military's example,

Rank predicted care in our sample,

The mighty were heeded o'er the smal.