Maria Ibanez - Faculty & Research - Harvard Business School
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Maria Ibanez

Doctoral Student

Maria Ibanez is a doctoral candidate and teaching fellow in the Technology and Operations Management unit at the Harvard Business School. Prior to joining HBS, she earned a Master of Science in Applied Economics from Marquette University and conducted research at the University of Chicago with Professor Steven Levitt. 

Maria's research investigates how to improve performance by designing data-driven systems that lead individuals to make better decisions. In doing so, her research seeks to help individuals improve how they exercise discretion and increase their productivity. With a primary focus on healthcare, she collaborates with organizations to understand their work and to develop implementable solutions for relevant challenges. Combining operations management with economic theory and the psychology of decision-making, she analyzes large-scale field data to identify causal relationships that generate new scholarly insights regarding the connections between operational factors, decision-making, and performance. 
Her recent research focuses on the sequencing of decision-making. From physicians seeing patients to auditors inspecting establishments, many jobs entail completing a series of sequential, independent tasks. Maria’s work explores (1) how the sequencing of decision-making affects the decisions we make and (2) the consequences of exercising discretion to deviate from the prescribed sequence in which tasks are arranged for us (self-organization of work). Overall, her research documents the conditions under which individuals make better decisions and highlights opportunities to improve decision-making by being mindful about the order in which we make those decisions. 

In her spare time, Maria enjoys volunteering, and has participated in medical brigades in Latin America as well as acted as a consultant for small businesses in need of technical expertise. 

To read more about Maria's research and teaching, visit her personal web site
Journal Articles
  1. Discretionary Task Ordering: Queue Management in Radiological Services

    Maria Ibanez, Jonathan R. Clark, Robert S. Huckman and Bradley R. Staats

    Work-scheduling research typically prescribes task sequences implemented by managers. Yet employees often have discretion to deviate from their prescribed sequence. Using data from 2.4 million radiological diagnoses, we find that doctors prioritize similar tasks (batching) and those tasks they expect to complete faster (shortest expected processing time). Moreover, they exercise more discretion as they accumulate experience. Exploiting random assignment of tasks to doctors’ queues, instrumental variable models reveal that these deviations erode productivity. This productivity decline lessens as doctors learn from experience. Prioritizing the shortest tasks is particularly detrimental to productivity. Actively grouping similar tasks also reduces productivity, in stark contrast to productivity gains from exogenous grouping, indicating deviation costs outweigh benefits from repetition. By analyzing task completion times, our work highlights the tradeoffs between the time required to exercise discretion and the potential gains from doing so, which has implications for how discretion over scheduling should be delegated.

    Keywords: discretion; scheduling; queue; healthcare; learning; experience; Decentralization; operations; service operations; service delivery; Performance; Performance Effectiveness; Performance Efficiency; Performance improvement; Performance Productivity; Decisions; time management; Cost vs Benefits; Health Industry; Operations; Service Operations; Service Delivery; Performance; Performance Effectiveness; Performance Efficiency; Performance Improvement; Performance Productivity; Decisions; Time Management; Cost vs Benefits; Health Industry;


    Ibanez, Maria, Jonathan R. Clark, Robert S. Huckman, and Bradley R. Staats. "Discretionary Task Ordering: Queue Management in Radiological Services." Management Science 64, no. 9 (September 2018): 4389–4407. (Working paper available here. Winner of the 2017 Best Paper Competition of the POMS College of Healthcare Operations Management. Featured in Forbes, Quartz, and Inc.)  View Details
  2. Commercial Property Rent Dynamics in U.S. Metropolitan Areas: An Examination of Office, Industrial, Flex and Retail Space

    Maria Ibanez and Anthony Pennington-Cross

    This paper is concerned with the market rental rate for space offered by commercial property and how that rental rate evolves over time. Rental rates reflect the value of the services provided by the property and can have a significant impact on the ability of its owners to make monthly debt obligations. We investigate commercial property rent dynamics for 34 large metropolitan areas in the U.S. The dynamics are studied from the second quarter of 1990 through the second quarter of 2009 and the results are compared across four property types or uses (office, industrial, flex, and retail). There is substantial heterogeneity in both the long and short run responses to changing demand and supply conditions. In general, the office market is the slowest to adjust back towards equilibrium while industrial and flex markets adjust back to the long run equilibrium very quickly. For industrial and office types, the speed of adjustment is substantially faster within quality segments and is strongest for grade A properties.

    Keywords: Commercial Real Estate; Rent Dynamics; Office property; Flex property; Retail property; Industrial property; Property; Real Estate Industry; United States;


    Ibanez, Maria, and Anthony Pennington-Cross. "Commercial Property Rent Dynamics in U.S. Metropolitan Areas: An Examination of Office, Industrial, Flex and Retail Space." Journal of Real Estate Finance and Economics 46, no. 2 (February 2013): 232–259.  View Details
Working Papers
  1. How Scheduling Can Bias Quality Assessment: Evidence from Food Safety Inspections

    Maria Ibanez and Michael W. Toffel

    Many production processes are subject to inspection to ensure they meet quality, safety, and environmental standards imposed by companies and regulators. Inspection accuracy is critical to inspections being a useful input to assessing risks, allocating quality improvement resources, and making sourcing decisions. This paper examines how the scheduling of inspections risks introducing bias that erodes inspection quality by altering inspector stringency. In particular, we theorize that inspection results are affected by (a) the inspection outcomes at the inspector’s prior inspected establishment and (b) when the inspection occurs within an inspector’s daily schedule. Analyzing thousands of food safety inspections of restaurants and other food-handling establishments, we find that inspectors cite more violations after inspecting establishments that exhibited worse compliance or greater deterioration in compliance and that inspectors cite fewer violations in successive inspections throughout their day and when inspections risk prolonging their typical workday. Our estimates suggest that, if the outcome effects were amplified by 100% and the daily schedule effects were fully mitigated (that is, reduced by 100%), the increase in inspectors’ detection rates would result in their citing an average of 9.9% more violations. Scaled nationwide, this would yield 19 million fewer foodborne illness cases per year, reducing annual foodborne illness costs by $14.2 billion to $30.9 billion. Understanding these biases can help managers develop alternative scheduling regimes that reduce bias in quality assessments in domains such as food safety, process quality, occupational safety, working conditions, and regulatory compliance.

    Keywords: Assessment; quality; bias; inspection; scheduling; Econometric Analysis; Empirical Research; regulation; Health; Food; Safety; Quality; Performance Consistency; Performance Evaluation; Food and Beverage Industry; Service Industry;


    Ibanez, Maria, and Michael W. Toffel. "How Scheduling Can Bias Quality Assessment: Evidence from Food Safety Inspections." Harvard Business School Working Paper, No. 17-090, April 2017. (Revised April 2018. Formerly titled "Assessing the Quality of Quality Assessment: The Role of Scheduling". Featured in Forbes, Food Safety Magazine, and Food Safety News.)  View Details
Managerial Articles
  1. The Answer is 9,142: Understanding the Influence of Disruption Risk on Inventory Decision Making

    Mark Cotteleer, Maria Ibanez and Geri Gibbons

    The question was how many units of inventory a manager should order when faced with a possible disruption in supply. The correct answer is not guesswork, but based on 150 years of theory and practice. We examine individual choices made in this critical situation—and the results are not encouraging.

    Keywords: Behavioral; behavioral operations; Inventory; bias; operations; operations management; Operations;


    Cotteleer, Mark, Maria Ibanez, and Geri Gibbons. "The Answer is 9,142: Understanding the Influence of Disruption Risk on Inventory Decision Making." Deloitte Review 14 (January 2014).  View Details
Book Chapters
  1. Behavioral Empirics and Field Experiments

    Maria Ibanez and Bradley R. Staats

    As the study of behavioral operations has continued to grow, an increasing number of researchers are turning to the field (e.g., conducting observational studies or natural or field experiments) to push deeper in order to find the answers to relevant behavioral questions. Field data can bring richness to any study seeking to explain real world phenomena and can complement lab experiments. This not only creates the potential for additional insight, but it also helps to overcome methodological challenges (while at the same time adding new challenges). By turning to the field, it is possible to expand the scope of behavioral operations management such that it continues to build theory that is both rigorous and relevant. Altogether we hope this chapter will aid behavioral operations management scholars in utilizing a variety of empirical approaches to conduct research that utilizes field data to advance scholarship and practice.

    Keywords: behavioral operations; empirical operations; empirical operations management; Field Experiments; Behavior; Operations; Management; Research;


    Ibanez, Maria, and Bradley R. Staats. "Behavioral Empirics and Field Experiments." In The Handbook of Behavioral Operations, edited by Karen Donohue, Elena Katok, and Stephen Leider. New York, NY: John Wiley & Sons, forthcoming.  View Details