umd logo



photo of me


Mary Zaki

Assistant Research Professor
Department of Agricultural & Resource Economics
University of Maryland
mzaki@umd.edu

CV
Research
Teaching


Brief Biography

Mary's research focuses on household finance and household consumption issues especially among low income populations.  She currently is studying household spending patterns between paycheck receipts, the effects of high cost credit on food consumption among military families, the influence of food acquisition costs on food stamp month spending, historical consumer credit costs and the effect of school breakfast program expansions on health outcomes and test scores. She received her B.S. and B.A. in Economics from the University of Pennsylvania and her M.S. and Ph.D. in Economics from Northwestern University. 


Research

Price Consciousness at the Peak of Impatience,” with Jessica Todd (Accepted: Journal of Human Resources)
Past studies have consistently documented that consumption among low-income households spikes soon after receipt of income and subsequently declines over time. Using two approaches to analyzing linked survey and administrative data on food purchases, we find that SNAP recipients are most price-conscious and engage in their most successful price-saving efforts soon after receipt of benefits. This finding contrasts with prior literature that posits recipients mistakenly feel "flush" with money after benefit receipt. Rather, it injects forethought and savviness on the part of SNAP recipients into the prevailing narrative that they lack self-control and capability. It is possible that the frequency of benefit receipt acts as a savings commitment device that funds price-saving efforts.

Employed in a SNAP? The Impact of Work Requirements on Program Participation and Labor Supply,” with Colin Gray, Adam Leive, Elena Prager and Kelsey Pukelis (Conditionally Accepted: American Economic Journal: Economic Policy)
Work requirements are common in U.S. safety net programs. Evidence remains limited, however, on the extent to which work requirements increase economic self-sufficiency or screen out vulnerable individuals. Using linked administrative data on food stamps (SNAP) and earnings with a regression discontinuity design, we find robust evidence that work requirements increase program exits by 23 percentage points (64 percent) among incumbent participants after 18 months. There is a 53 percent overall reduction in program participation among adults who are subject to work requirements. Homeless adults are disproportionately screened out. We find no effects on employment, and suggestive evidence of increased earnings in some specifications. Our findings indicate that, per dollar of public expenditure, eliminating work requirements would likely transfer more resources to low-income adults than other programs targeting the same population.

Access to Short-term Credit and Consumption Smoothing within the Paycycle,” (Revise and Resubmit: Review of Economics and Statistics)
I use high-frequency data to identify if access to expensive small dollar credit makes household day-to-day life harder or easier. Using a newly obtained military administrative dataset of daily sales at on-base grocery stores, I examine how consumption behavior changes after the passage of a federal law that effectively bans military personnel from accessing payday loans in some states but not in others. The military setting is ideal for this analysis because military personnel are assigned to locations across the United States with varying degrees of access to payday loans. Furthermore, since military personnel face varying known wait times between paycheck receipts throughout the year, I can examine daily consumption patterns. I find that payday loan access enables consumers to better smooth their consumption between paychecks, with no detectable effect on the total amount of food consumed. These patterns reveal that more households become less liquidity constrained when they have access to payday loans. However, I also find suggestive evidence that they lead to temptation purchases. Military personnel purchase more alcohol and electronics when given access to payday loans. Further evidence suggests that there may be significant heterogeneity in the population, with indications of present-biased preferences among some individuals and forward-looking behavior among others.

Expanding the School Breakfast Program: Impacts on Children's Consumption, Nutrition and Health,” with Diane Whitmore Schanzenbach (Revise and Resubmit: Journal of Policy Analysis and Management)
We exploit unique features of a previously conducted randomized experiment to determine the effectiveness of varying implementations of School Breakfast Program (SBP) expansions that increase children's access to breakfast. We find that simply moving eating location to the classroom, even without changing breakfast timing to the school day, can significantly increase program take-up. We document heterogeneous impacts on other outcomes with lower-income students having marginally worse health and performance outcomes than higher-income students. In light of the proliferation of legislation that mandates After-the-bell Breakfast implementations, our results encourage a more personalized and carefully monitored approach to SBP expansion in order to confirm a beneficial outcome for a given student population.

The Other Mental Defaults of Non-salient Prices,”
The overwhelming majority of empirical studies find that consumers underestimate or underreact to prices that are not salient. Using two framed field experiments in a common consumer setting, I identify that consumers can consistently overestimate and overreact to non-salient prices. This departure from standard findings is consistent with consumers assigning high "mental defaults" to prices that they pay no attention to in a costly attention framework. I identify that high mental defaults originate from prior experiences/beliefs in the consumer setting rather than from aversion to price uncertainty. I also find that people can switch mental defaults depending on the task at hand, demonstrating that mental defaults for a price need not be internally consistent and equal to the expected value.

Interest Rates: Prices Hidden in Plain Sight,”
I construct a new record of credit terms from mail-order catalogs of the 20th Century (e.g., Sears, Montgomery Ward) and find that when creditors switched from dollar to interest rate price disclosure in the 1960s, credit prices starkly jumped and became almost unresponsive to movements in underlying cost-of-funds. I investigate possible explanations by using accompanying historical evidence and conjecture that the shift in price disclosure method diminished consumer ability to determine credit cost obligations and subsequently creditor incentives to compete on price.

Works in Progress

“Watt Watchers & the Seesaw of Energy Dieting: Evidence from Low-income Urban Households,” with Sebastien Houde and Catherine Wolfram

“Grocery Delivery and Healthy Eating Incentives in Low Food Access Areas”

Teaching

AREC250 - Elements of Agricultural and Resource Economics

AREC489O/AREC 426, Economic Methods and Food Consumption Policy