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 Research, Redmond, WA
99/4623, 14820 NE 36th St, Redmond, WA 98052
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 (F1 Visa with STEMP OPT option)


“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). Conditionally accepted in the American Economic Journal: Applied Economics. (Link here)

In clustered paired experiments, units are matched into pairs, and one unit of each pair is randomly assigned to treatment. To estimate the treatment effect, researchers often regress their outcome on a treatment indicator and pair fixed effects, clustering standard errors at the unit-of-randomization level. We show that the variance estimator in this regression may be severely downward biased: under constant treatment effect, its expectation equals 1/2 of the true variance. Instead, researchers should cluster their standard errors at the pair level. Using simulations, we show that those results extend to stratified experiments with few units per strata.

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

We explore firm-level markup and profit rates during the COVID-19 pandemic for a panel of 3,548 publicly-traded firms in Compustat and find increases for the average firm. Those increases can be captured by previous trends in market power and profitability. Furthermore, focusing on the average firm masks large heterogeneity in the disruption caused by the pandemic. We complement our analysis by studying heterogeneity by pre-pandemic baseline markup rates, firm size, stock-exchange tenure, employment, profitability, and market share. We find that firms that have lower profitability than what we could expect from their previous trends tend to have lower markup rates, higher market shares, and more 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


2022: RCEA Econometrics Conference, 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


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: 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