Jaime Ramirez-Cuellar


Email | CV | Research | Teaching
2019 North Hall, Santa Barbara, CA 93106-9210, USA

View the Project on GitHub jdramirezc/cv

Jaime Ramirez-Cuellar

Senior Research Economist at Microsoft
Redmond, WA
Email: jrc@econ.ucsb.edu
(PDF version available here)


University of California, Santa Barbara, CA
Ph.D. in Economics, 2022
M.A. in Economics, 2017

National University of Colombia, Bogotá, Colombia
M.S. in Economics, 2012
B.S. in Economics, 2011


Econometrics, Labor Economics


Colombian (US Permanent Resident)


“Testing for Idiosyncratic Treatment Effect Heterogeneity." (Link here)

This paper provides asymptotically valid tests for the null hypothesis of no treatment effect heterogeneity. Importantly, I consider the presence of heterogeneity that is not explained by observed characteristics, or so-called idiosyncratic heterogeneity. When examining this heterogeneity, common statistical tests encounter a nuisance parameter problem in the average treatment effect which renders the asymptotic distribution of the test statistic dependent on that parameter. I propose an asymptotically valid test that circumvents the estimation of that parameter using the empirical characteristic function. A simulation study illustrates not only the test’s validity but its higher power in rejecting a false null as compared to current tests. Furthermore, I show the method’s usefulness through its application to a microfinance experiment in Bosnia and Herzegovina. In this experiment and for outcomes related to loan take-up and self-employment, the tests suggest that treatment effect heterogeneity does not seem to be completely accounted for by baseline characteristics. For those outcomes, researchers could potentially try to collect more baseline characteristics to inspect the remaining treatment effect heterogeneity, and potentially, improve treatment targeting.


“At What Level Should One Cluster Standard Errors in Paired and Small-Strata Experiments?" (with Clément de Chaisemartin). Accepted in the American Economic Journal: Applied Economics. (Link here)

In clustered and paired experiments, to estimate treatment effects, researchers often regress their outcome on the treatment and pair fixed effects, clustering standard errors at the unit-of-randomization level. We show that even if the treatment has no effect, a 5%-level t-test based on this regression will wrongly conclude that the treatment has an effect up to 16.5% of the time, an error rate much larger than the researcher’s 5% target. To achieve their targeted error rate, researchers should instead cluster standard errors at the pair level. Using simulations, we show that similar results apply to clustered experiments with small strata.

“The Pandemic Effects on Market Power and Profitability” (with Juan Espinosa-Torres). (Link here) (Submitted)

We explore firm-level markup and profit rates during the COVID-19 pandemic for a panel of 3,611 publicly traded firms in Compustat and find increases for the average firm. We offer conditions to give markups and profit rate forecasts a causal interpretation of what would have happened had the pandemic not happened. Our estimations suggest that had the pandemic not happened, markups would have been 4% and 7% higher than observed in 2020 and 2021, respectively, and profit rates would have been 2.1 and 6.4 percentage points lower. We perform a battery of tests to assess the robustness of our approach. We further show significant heterogeneity in the impact of the pandemic on firms by key firm characteristics and industry. We find that firms with lower than forecasted markups tend to have lower stock-exchange tenure and fewer employees.


Dissertation Committee


University of California, Santa Barbara, CA

Teaching Assistant

Los Andes University, Bogotá, Colombia
Lecturer, Macroeconomics I (Undergraduate), Aug-Nov 2013
Teaching Assistant, Financial Markets (Undergraduate), Feb-May 2014

Rosario University, Bogotá, Colombia
Lecturer, International Trade (Undergraduate), Feb-Jun 2011

National University of Colombia, Bogotá, Colombia
Teaching Assistant


University of California, Santa Barbara, CA
Research Assistant to Professors Richard Startz, Douglas Steigerwald, and Finn Kydland
Projects: Structural Econometrics, Bayesian Econometrics, Regime Switching Tests, Andhra Pradesh Priorities, 2017-2019
Newsletter Contributor, LAEF, Summers 2018, 2019, 2020

Inter-American Development Bank, Washington, DC, Jul 2014-Jul 2016
Research Fellow to Eduardo Cavallo, Julian Caballero, Andrés Fernández, Carola Pessino, and Ernesto Stein

Office of the Colombian Financial Supervisor, Bogotá, Colombia
Senior Analyst, Research and Development Directorate, May 2013-Jun 2014

Fedesarollo, Bogotá, Colombia, Feb 2011-May 2013
Research Assistant to Leonardo Villar, Roberto Steiner, Natalia Salazar, and Adolfo Barajas


Prize for Scholarship, Teaching, and Service, UCSB, Fall 2020
Research Quarter Fellowship, UCSB, Fall 2019
Costas Fellowship, UCSB, Spring 2019
Gretler Fellowship, UCSB, Summer 2018
Jennifer Jo Williamson Fellowship, UCSB, Fall 2017
UC Regents Fellowship, UCSB, 2016-2017
Distinction in Ph.D. Preliminary Examination in Econometrics and Microeconomics, UCSB, 2017
Fulbright and Colfuturo’s Excellence Group, 2012
Scholarship for Master Studies, Fedesarrollo, Feb-May 2012


2023: Midwest Economics Association
2022: RCEA Econometrics Conference, Microsoft Research, Econometric Society Australasian Meetings
2020: American Causal Inference Conference (postponed)
2019: Advances in Field Experiments (U Chicago), California Econometrics Conference (UC Davis), Econometric Society’s Latin American Meetings (Puebla), Los Angeles Conference in Applied Economics (USC)


American Economic Association, Econometric Society, Latin American and Caribbean Economic Association, Broom Center for Demography, American Society of Hispanic Economists, European Economic Association, Midwest Economics Association


Referee for: Econometrica
Referee for: Review of Economics and Statistics
Referee for: Microsoft Journal of Applied Research
Referee for: Oxford Bulletin of Economics and Statistics
Conference Organizer: Southern California Graduate Conference in Applied Economics, 2020
Discussant: Los Angeles Conference in Applied Economics, 2019

Mentor: American Economics Association - CSQIEP, 2022-23
Mentor: Graduate Division Scholars Program, UCSB, 2021
Member of Economics Diversity Task Force, UCSB, 2020
Mentor: Economics Graduate Student Association, UCSB, 2019
Community outreach: California Forum for Diversity in Graduate Education at CSU Channel Islands, 2017
Mentor: National University of Colombia Alumni Program, 2017


Stata Workshop, Broom Center, UCSB, Dec 2020
Stata Skills, UCSB (Undergraduate), Summer 2020
Data Hack in R, UCSB (Undergraduate), Summers 2018, 2019


R, Stata, Matlab, Python, PySpark, RStan, SQL, UNIX, Eviews,


English (Fluent), Spanish (Native), Portuguese (Advanced)

Updated: August 2022