9:30–10:45 | Keynote speaker 1 (Amphitheater)Two-way fixed effects and difference in differences with heterogeneous treatment effects: A survey Abstract: Linear regressions with period and group fixed effects are widely used to estimate policies' effects: of the 100 most cited papers published by the American Economic Review from 2015 to 2019, 26 estimate such regressions.
It has recently been shown that those regressions may produce
misleading estimates if the policy's effect is heterogeneous
between groups or over time, as is often the case. This survey
reviews a fast-growing literature that documents this issue and
proposes alternative estimators robust to heterogeneous
effects.
Xavier d'Haultfoeuille
CREST-ENSAE
|
11:15–12:15 | Education session (Amphitheater) |
11:15–11:45 | University proximity at teenage years and educational attainment
Abstract:
This presentation investigates the impact of geographical proximity to
universities on educational attainment in Nigeria.
I relate individuals' level of schooling obtained from three
rounds of the Nigeria Living Standard Measurement Survey
(LSMS) to spatial distance too university measured by pairing
residential and university campuses, GPS coordinates. To
identify the effect of the distance to the university, I exploit
the theory of residential sorting to instrument residential
proximity to the university. Specifically, I instrument distance
to the university drawing on variations in households’ proximity to
state boundary posts and neighborhood population density. The
instrumental variable estimates show a negative and significant
effect of distance, revealing that geographical constraints
during teenage years represent a barrier to the subsequent human
capital acquisition. Additional results from a
difference-in-difference estimation strategy indicate that a
large-scale establishment of universities had beneficial
trickle-down effects by decreasing the intention to drop out of
secondary school, supporting evidence of the role of
geographical constraints in the accumulation of human capital in
Nigeria.
Additional information:
Oussama Ben Atta
Université de Pau et des Pays de l'Adour
|
11:45–12:15 | Peer competition: Evidence from 5- to 95-year-olds
Jose De Sousa
Université Paris-Saclay
|
11:15–12:15 | Globalization and migration session (Room 21) |
11:15–11:45 | Violence and migration: The role of police killings in the Venezuelan diaspora
Abstract:
During the 2010s, Venezuela underwent the worst and deepest
crisis of any non-war-ridden country in modern history.
The failure of the socialist utopia, the economic crisis, the
increasing lack of primary resources, and the dictatorial turn
have caused the third, most dramatic, and complex Venezuelan
out-migration wave in the past decade. Drawing on exclusive and
georeferenced survey data collected in Venezuela and providing
information on 21,382 individuals, this presentation investigates
the role of the police force militarization in the Venezuelan
migration crisis of 2018. I find that the higher the level
of authoritative violence—proxied by the share of homicides
committed by the security forces—the higher the likelihood
is for an individual to migrate. The effect is significant only
among males with a lower level of education. Estimates that
rely on the travel time from the capital to each state’s most
populated city as an instrumental variable are robust to the
inclusion of several households and environmental and sociodemographic
characteristics, including the overall level of
violence represented by the number of violent deaths per 100,000
inhabitants.
Additional information:
Carlo Caporali
Gran Sasso Science Institute
|
11:45–12:15 | Emigration intentions and risk aversion: Causal evidence from Albania
Abstract:
Estimating the impact of risk aversion on emigration at the
individual level is complicated by selection issues.
In this presentation, I use original data from Albania on mobility
intentions and elicited risk aversion to provide causal
estimates on this relationship. My identification strategy
relies on the occurrence of two earthquakes during data
collection that unambiguously led to upward shifts in risk
aversion as shown in an article by Beine et al. (2021).
While OLS estimates fail to capture a (negative) relationship
between risk aversion and emigration intention, a control
function strategy using the two earthquakes as instruments
uncovers such a relationship. I argue that my results
highlight a new channel through which risk preferences explain
the trapped population phenomenon documented in the climate
change and migration literature.
Additional information:
Michel Beine
University of Luxembourg
|
2:00–3:30 | Employment session (Room 21) |
2:00–2:30 | The multiple dimensions of selection into employment
Abstract:
A vast literature on gender wage gaps has examined the
importance of selection into employment.
However, most analyses have focused only on female labor-force
participation and gaps at the median. The Great Recession
questions this approach, not only because of the major shift in male
employment that it implied but also because women’s decision
to participate seems to have been different along the
distribution, particularly because of an “added worker effect”.
This presentation uses the methodology proposed by Arellano and
Bonhomme (2017) to estimate a quantile selection model over the
period 2007–2018. Using a tax and benefit microsimulation model,
I compute an instrument capturing the male selection induced by
the crisis as well as female decisions: the potential
out-of-work income. Because my instrument is crucially determined
by the welfare state, I consider three countries with notably
different benefit systems—the U.K., France, and Finland. My
results imply different selection patterns across countries and
a sizeable male selection in France and the U.K. Correction for
selection bias lowers the gender wage gap and, in recent
years, reveals an increasing shape of the gender gap
distribution with a substantial glass ceiling for the three
countries.
Additional information:
Kenza Elass
Aix-Marseille Université, AMSE
|
2:30–3:00 | Temporary employment and poverty persistence: The case of U.K. and Germany
Abstract:
This presentation aims at providing more insight on the relationship
between atypical employment and poverty, with a focus on
temporary contract workers.
I want to assess to what extent temporary contract workers face
higher risk of poverty than standard workers and how factors
such as the family structure and the welfare states influence
this risk. I study the implication of being under temporary
contract on the risk of poverty in a longitudinal perspective in
order to investigate further the association between atypical
work and poverty not only by contract type and individual
characteristics as done in two previous dynamic
analyses—Debels (2008) and Amuedo-Dorantes and Serrano-Padial
(2010)—but also by the households’ financial situation, the
role of the partners’ earnings and benefits, while controlling
for feedback effects of contract type and state dependency of
poverty as done by Amuedo-Dorantes and Serrano-Padial (2010). In
order to do that, I use two large panels for Germany (SOEP) and
the U.K. (BHPS-UKHLS). Those panels allow me to cover extended periods:
SOEP goes from 1984 to 2017 and the U.K. from 1991 to 2019.
Additional information:
Agathe Simon
University of Strasbourg - BETA
|
3:00–3:30 | A counterfactual analysis of the gender wage gap: A new microevidence from the Tunisian labor market
Abstract:
This presentation aims to measure the gender wage gap in the Tunisian
labor market.
My investigation essentially extends the traditional
Oaxaca-Blinder decomposition technique (1973). It also proposes
a counterfactual analysis along the entire wage distribution.
The fundamental basis of this method is to set up a
counterfactual distribution that allows us to estimate the
male-female wage gap at each quantile. As shown in my empirical
analysis, the gender pay gap does not refer to the differences
in observable characteristics between males and females. It is
rather the outcome of discriminatory practices against women.
Sofiene Omri
University of Carthage
|
2:00–3:30 | Health I session (Amphitheater) |
2:00–2:30 | Replaced or depressed? The effect of automation risk on workers' mental health
Abstract:
Automation may destroy jobs, change the labor demand structure
and different aspects of work, and may therefore impact
workers’ health.
Using French survey data, I estimate the effects of automation
risk on workers’ well-being and mental health. Implementing
the propensity-score matching method to solve the issue of
endogenous exposure to automation risk, I find that workers
exposed to the risk of automation have a higher probability to
declare anxiety or depression and to have a low self-assessed
well-being by five to six percentage points.
Additional information:
Sylvie Blasco
Le Mans Université
|
2:30–3:00 | The causal impact of remote working on depression during the first wave of the COVID-19 pandemic
Abstract:
I use longitudinal data from the SHARE survey to estimate the
effect of remote working during the Covid-19 pandemic on
depression in senior Europeans.
There are potential endogeneity concerns both for the
probability of remaining employed during the pandemic and,
conditional on employment, for the choice of work arrangements.
My research design overcomes these problems by exploiting the
occupational variations in the technical feasibility of remote
working and sectoral differences in the legal restrictions on
in-presence work. I find that remote working increases the
probability of reporting feelings of sadness or depression. This
effect is larger for women, respondents with children at home,
and singles, as well as in regions with more restrictive
containment policies and low-excess death rates. My results
should alert policy makers to the potential adverse consequences
of remote working for mental health in the post-pandemic
situation.
Additional information:
Danilo Cavapozzi
Ca' Foscari University of Venice
|
3:00–3:30 | Health and quality of life in aging populations: A structural equation modeling approach
Abstract:
Higher life expectancy and lower fertility rates are changing
the global population structure, leading to a fast-growing
aging society.
To face this societal challenge, governments worldwide are
increasing public expenditures focusing on healthy aging. The
objective of these investments is to increase quality of life
among older people. However, there is a lack of studies focused
on understanding the extent to which a wide range of
demographic, socioeconomic, and health characteristics are
associated with quality of life in advanced ages. Therefore, the
objective of this presentation is to explore the role of a variety of
factors toward quality of life, with a particular focus on
health. Structural equation modeling (SEM) is employed using
Stata 16 to explore these associations, using data drawn from
the Survey of Health, Ageing and Retirement in Europe (SHARE).
Contrary to many studies that use self-assessed single-item
questions or additive indices to measure unobserved concepts,
such as health and quality of life, this presentation models such
constructs as latent variables. Moreover, a minor contribution
of this presentation is to employ standard statistical techniques using
additive indices along with the main SEM estimation. As the
theory predicts, estimates found with additive indices are
downward biased compared with latent variables, but so far, there
are no studies showing this empirical exercise. The overall
findings suggest that nonpecuniary factors, especially physical
health status and participating in social activities, play a
larger role in enhancing quality of life in advanced age
compared with pecuniary factors such as income and financial
assets. Therefore, greater attention should be paid on
non-economic factors to enrich quality of life among an
increasingly aging population.
Additional information:
Chiara Costi
Lancaster University
|
4:00–5:00 | Invited StataCorp speaker (Amphitheater)Econometrics strikes back: GMM and two-way fixed effects Abstract: Two-way fixed effects is not a broken methodology. As Wooldridge (2021) shows, the estimator can be used to obtain heterogeneous treatment effects.
I illustrate how to obtain these treatment effects using GMM.
Additionally, I show how some other proposed estimators for
heterogeneous treatment effects can be fit using GMM.
Additional information:
Enrique Pinzón
StataCorp
|
9:30–11:00 | Public policy session (Room 21) |
9:30–10:00 | The role of the financial constraint in STW policy success during and after the Great Recession
Abstract:
Just one year after the subprime crisis, and despite being one
of the most impacted countries in the world, Germany displayed
the highest GDP growth rate among EU countries and maintained it
at its level for two years.
Combined with a surprisingly small variation in unemployment
rates over this period, some press articles have nicknamed the
impressive German economic recovery the "second German
miracle". In this presentation, I produce empirical evidence of the
role played by short-time work in the "German miracle". By
exploiting firm-level data, I show that short-time work programs
should target firms facing huge financial constraints and
difficult business conditions. To these conditions, short-time
work programs can preserve employment during a crisis and allow
a greater take-up afterward.
Additional information:
Nathan Vieira
Aix-Marseille Université, AMSE
|
10:00–10:30 | The impact of a European unemployment benefit scheme on labor supply and income distribution
Abstract:
This presentation investigates the effect of the introduction of a
European unemployment insurance scheme (EMU-UI) on the labor
supply and the income distribution in the Eurozone countries.
Based on a structural estimation of the labor supply and using
the European tax-benefit microsimulation model EUROMOD, I
simulate various scenarios of reform. The results show that the
labor supply response to the introduction of an EMU-UI differs
substantially across countries and depends on the design of the
EMU-UI. I find that a flat EMU-UI scheme implies very strong
disincentive to work but reduces poverty. On the contrary, a
fully contribution-related EMU-UI system limits much more the
distortions on the labor market in most countries but has
limited effects on poverty and inequality. An EMU-UI with a
common replacement rate, articulated with floor and ceiling
amounts, would allow for upward convergence because it would
strongly reduce poverty and inequality in several countries
while not inducing important labor supply reduction.
Additional information:
Agathe Simon
University of Strasbourg - BETA
|
10:30–11:00 | The impact of COVID-19 restrictions on economic activity: Evidence from the Italian regional system
Abstract:
Nonpharmaceutical interventions adopted by governments to halt
the spread of Sars-Cov2 are thought to have nontrivial
consequences for the economy.
The purpose of this presentation is to estimate the economic impact of
nonpharmaceutical interventions in Italy by taking advantage
of timing differences in their implementation across regions. To
achieve this, I estimate one-way and two-way fixed effects
models on a large sample of Italian provinces. I also isolate a
set of well-defined natural experiments in which one region goes
from a lower to a higher tier of restrictions, while a
neighboring region remains in the lower tier, for which we can
estimate difference-in-differences and continuous treatment
models. Moreover, in order to observe whether the impact of
restrictions has changed over time, I split the sample around
December 2020 and replicate the analysis in each subsample. My
case studies indicate that an Italian province moving from tier
2 to tier 3 in the system of restrictions can expect a fall in
mobility of between 12 and 18 percentage points. Thus, I
provide evidence of the negative effects of nonpharmaceutical
interventions on economic activity. Finally, I provide some
evidence that the effectiveness of nonpharmaceutical interventions
in reducing mobility is likely to reduce over time, which has
important policy implications.
Additional information:
Brian Cepparulo
University of Greenwich
|
9:30–11:00 | International economics session (Amphitheater) |
9:30–10:00 | Improving the estimates of fiscal space
Abstract:
I contribute to the fiscal space literature in both technical
and empirical perspectives.
First, I compute a time-varying fiscal space and show that
complex fiscal space numbers resulting from solving the model
provide crucial information in assessing fiscal sustainability;
thus, they should not be ignored. I propose three different
scenarios to deal with complex numbers in an empirical
framework. Second, I provide a new determinant for fiscal
sustainability: sustainable development. Using data from 24
OECD countries from 1998–2015, I find that sustainable
development, proxied by an environmental, social, and governance
performance index, has a robust positive impact on fiscal space.
Additional information:
Adham Jaber
Université Paris1 Panthoén-Sorbonne
|
10:00–10:30 | Better two eyes than one: A synthesis classification of exchange rate regimes
Abstract:
This presentation proposes a new de facto classification of exchange
rate regimes, the synthesis classification.
The proposed framework has several advantages over existing de
facto classifications. First, it offers a unified framework
based on the most divergent classifications, the RR and LYS
classifications, leading not only to a broader coverage but also
to a broader spectrum of exchange systems. Second, it
fits better with the known history of exchange rate regimes
developments in the post-Bretton Woods era. Among other things, it
brings an interesting nuance to the so-called hollowing-out
hypothesis by showing that the evolution of de facto
regimes—especially in emerging economies since the late 1990s—has
essentially involved movement toward more tightly “managed”
intermediate regimes and not a shift away from such regimes. As
an illustration of the insightfulness of our classification, I
empirically revisit the nexus between currency crises and
exchange rate regimes. In addition to associate a higher
probability of currency crisis with both intermediate and floating
regimes, my classification, also displays better statistical
performances than other classifications in predicting currency
crises.
Additional information:
Carl Grekou
CEPII
|
10:30–11:00 | Efficient estimation of spatial econometrics models with skewed and heavy-tailed distributed errors
Abstract:
In spatial econometrics, estimation of models by maximum
likelihood (ML) generally relies on the assumption of normally
distributed errors.
While this approach leads to highly efficient estimators when
the distribution is Gaussian, GMM might yield more efficient
estimators if the distribution is misspecified. For the SAR
model, Lee (2004) proposes an alternative QML estimator that is
less sensitive to the violation of the normality assumption. In
this presentation, I derive an estimator that is highly efficient
for skewed and heavy-tailed distributions. More
precisely, I here assume that the distribution of the errors is
a Tukey g-and-h (Tgh). However, because the density
function of the Tgh has no explicit form, the optimization
program for the MLE needs a numeric inversion of the quantile
function to fit the model, which is a computationally demanding
task. To solve this difficulty, I rely on the local asymptotic
normality (LAN) property of spatial econometrics models to
propose an estimator that avoids such a computational burden.
My Monte Carlo simulations show that our estimator outperforms
the ones available as soon as the distribution of the errors
departs from Gaussianity either by exhibiting heavier tails or
skewness. I illustrate the usefulness of the suggested
procedure relying on a trade regression.
Additional information:
Vincenzo Verardi
Université de Namur
|
11:30–12:30 | Finance session (Room 21) |
11:30–12:00 | GAM(L)A: An econometric model for interpretable machine learning
Abstract:
Despite their high predictive performance, random forest and
gradient boosting are often considered as black boxes or
uninterpretable models, which has raised concerns from
practitioners and regulators.
As an alternative, I propose to use partial
linear models that are inherently interpretable. Specifically,
this presentation introduces GAM-lasso (GAMLA) and GAM-autometrics
(GAMA), denoted as GAM(L)A in short. GAM(L)A combines
parametric and non-parametric functions to accurately capture
linearities and nonlinearities prevailing between dependent and
explanatory variables and a variable-selection procedure to
control for overfitting issues. Estimation relies on a two-step
procedure building upon the double residual method. I
illustrate the predictive performance and interpretability of
GAM(L)A on a regression and a classification problem. The
results show that GAM(L)A outperforms parametric models
augmented by quadratic, cubic, and interaction effects. Moreover,
the results also suggest that the performance of GAM(L)A is not
significantly different from that of random forest and gradient
boosting.
Additional information:
Sullivan Hué
Aix-Marseille Université, AMSE
|
12:00–12:30 | Does relationship lending matter in an emerging market?
Abstract:
This presentation analyzes the impact of the intensity and duration of
bank-firm relationship on Tunisian loan quality over the period
2012–2018.
Estimating a panel-ordered probit model, my results indicate
that the impact of relationship lending (in the form of duration
and intensity) on loan quality is different according to the
firm’s profitability level. The intensity of the relationship
lending positively (negatively) impacts the loans of high
(average or low) quality. When intersecting intensity of a
banking relationship with firm balance sheet indicators, the
link between the intensity of the bank-firm relationship and
loan quality is lower (higher) for good- (low-) quality firms. In
addition, the length of the bank-firm relationship increases the
probability of poor-quality loans. These results show that
perverse and opportunist effects, in the form of strong moral
hazard, are persistent for firms at different levels of
profitability.
Naël Shehadeh
Aix-Marseille Université, AMSE
|
11:30–12:30 | Health II session (Amphitheater) |
11:30–12:00 | Is mass media an effective channel for conveying nutritional information? Welfare implications of the WHO classification of processed meats as carcinogenic on consumers in Israel
Abstract:
Disseminating health information in the mass-media seems like a
cost-effective approach to inform the public about the risks
involved in consuming hazardous food.
But does it work? I answer this question by exploiting the
announcement by the World Health Organization (WHO) in October
2015 that processed meat products have been classified as
carcinogenic to humans. My findings are based on two datasets,
a representative consumer panel data and aggregated
product-level market data of meat purchases in Israel. I apply
two different methods of natural-experiments: regression
discontinuity in time and difference-in-differences; both yield
similar results. It turns out that the WHO warning caused a
negative, sizable, statistically significant and persistent
change in the equilibrium quantities of processed meats, which
have dropped by 164 grams per household per month (-18%). To
produce an equivalent demand reaction, prices of processed meat
would have had to increase by 24%. The effect lasts for at least
two years, long after media coverage has faded. The response is
affected by income, ethnicity, and education. Low-income
households and immigrants from the former USSR did not
significantly respond to the announcement. Interestingly, I
find that secondary education on the part of one parent is a
necessary threshold for reducing long-term consumption. I
evaluate two values: (1) the price increase that would have
induced processed-meat consumption reduction equivalent to that
of the WHO announcement at 3.3-4.05 $/kg and (2) the marginal
expected cancer cost (through illness and mortality)
evaluated at 1.1-4.0 $/kg. As the two ranges overlap, I
conclude that the announcement successfully internalized the
costs associated with cancer risks into consumers'
considerations with respect to consumption of processed meat.
Additional information:
Adam Dvir
The Hebrew University of Jerusalem
|
12:00–12:30 | The impact of parents' health shocks on children's health behaviors
Abstract:
I evaluate whether parents’ health shocks in early childhood,
adolescence, or adulthood impact their children’s risky health
behavior.
I use a French epidemiological cohort. Two types of
health shocks are considered: lung cancer and smoking-related
cancer. First, I exploit heterogeneity in the age of the
individual at the moment of the parent’s health shock to
analyze the influence of the cancer diagnosis on the offspring's
smoking behavior. Second, I propose a Cox proportional hazards
model to study the impact of the age of the offspring at the
date of the diagnosis on the probability of quitting smoking.
Finally, I use the individual's smoking history to build a
retrospective panel and estimate an individual fixed-effects
model to identify the impact of the parent’s diagnosis on the
probability of smoking. In line with the existing literature, I
find in all cases very limited impact of the parent’s health
shock on the offspring's behavior.
Additional information:
Jérémy Tanguy
Université Savoie Mont Blanc
|
2:00–3:00 | Firms and labor session (Room 21) |
2:00–2:30 | Earnings dynamics, inequality, and firm heterogeneity
Abstract:
Studies of individual earnings dynamics typically ignore firm
heterogeneity, whereas worker and firm decompositions abstract
from the life cycle.
I study firm effects in individual earnings dynamics for the
Italian private sector population, using the covariance
structure of co-workers for identification. My model allows
for dynamics of both worker and firm effects, worker-firm
sorting, worker segregation, and correlation among connected
firms. While firms explain most of the earnings variance when
workers are young, workers explain most over the life cycle.
Sorting of workers across firms is substantial, especially for
younger workers. Standard earnings dynamics models overstate the
relevance of individual heterogeneity.
Paul Bingley
VIVE
|
2:30–3:00 | Monopsony in labor markets: Empirical evidence from Italian firms
Abstract:
I leverage on a matched employer-employee database drawn by an INPS
archive representative of the universe of Italian private sector
workers to investigate how labor market concentration affects
wages and employment.
I compute concentration measures relying
on new hires, finding that LMs aren’t on average
concentrated, despite showing relevant heterogeneity. I then
investigate the relationship between concentration and wages and
employment, finding negative correlations. I then develop an IV
strategy based on M&As to explore whether mergers increase
concentration at a market-level and to find a reliable source of
variation to identify their effect. First-stage estimates
indicate that only mergers raise concentration significantly,
while other events don’t. Estimated elasticities with
different IVs range between -0.09 and -0.14 p.p for wages and
between -0.68 and -0.77 p.p for hires.
Additional information:
Filippo Passerini
Catholic University of Milan
|
2:00–3:00 | Decisions session (Amphitheater) |
2:00–2:30 | Food tastes and trade liberalization
Lorenzo Rotunno
Aix-Marseille Université, AMSE
|
2:30–3:00 | Leadership communication and COVID-19 vaccination hesitancy
Abstract:
This presentation empirically analyzes the impact of leadership
communication on the COVID-19 vaccination rate using a
quasiexperimental design.
Based on a speech by the president of France, Emmanuel Macron,
I examine how political leaders can influence the willingness
of a country’s citizens to get vaccinated by transmitting
scientific insights into a clear and vivid message as well as by
threatening unvaccinated people with future restrictions.
In a difference-in-differences (DiD) framework, it is
shown that a televised address of Macron increased the
vaccination rate in France by roughly 5%. I test the robustness
of this result by applying an event-study design. My findings
imply that leadership communication is an effective weapon to
change the beliefs of unvaccinated citizens and to overcome
COVID-19 vaccination hesitancy.
Additional information:
Phil-Adrian Klotz
Justus-Liebig-University Giessen
|
3:30–4:30 | Keynote speaker 2 (Amphitheater)Using Stata to implement simple difference-in-differences estimators for staggered interventions Abstract: I show how to use built-in Stata commands to implement simple regression-based and treatment effects-based estimators in the context of staggered interventions with panel data.
Flexible models that allow substantial treatment-effect
heterogeneity—with and without covariates—are easy to
estimate in a variety of ways, including pooled OLS, doubly
robust methods, and matching estimators. The framework can be
used to both test for and correct for failure of the parallel
trends assumption.
Jeffrey Wooldridge
Michigan State University
|
4:30–5:15 | Open panel discussion with Stata developers
Contribute to the Stata community by sharing your feedback with StataCorp's developers. From feature improvements to bug fixes and new ways to analyze data, we want to hear how Stata can be made better for our users.
|
Nicolas Berman CNRS and AMSE |
Timothée Demont AMSE |
Habiba Djebbari AMSE |
Marion Dovis AMSE |
Phoebe W. Ishak AMSE |
Sébastien Laurent IAE and AMSE |
Mathieu Lefebvre AMSE |
Eva Moreno Galbis AMSE |
Vincenzo Verardi Université de Namur |
Roberta Ziparo AMSE |
The logistics organizers for the 2022 French Stata Conference are Aix-Marseille Université School of Economics and Timberlake Consultants, the Stata distributor to the United Kingdom and Ireland, France, Spain, Portugal, the Middle East and North Africa, Brazil, and Poland.
View the proceedings of previous Stata Conferences and Users Group meetings.