scholarly journals Mergers and difference-in-difference estimator: Why firms do not increase prices?

2014 ◽  
Vol 45 (2) ◽  
pp. 285-311 ◽  
Author(s):  
Juan Luis Jiménez ◽  
Jordi Perdiguero
Keyword(s):  
Difference In Difference ◽  
Difference Estimator

scholarly journals Food insecurity patterns before and after initial receipt of Supplemental Security Income

2019 ◽  
Vol 22 (10) ◽  
pp. 1909-1913 ◽  
Author(s):  
Rajan A Sonik ◽  
Susan L Parish ◽  
Monika Mitra
Keyword(s):  
Food Insecurity ◽  
Supplemental Security Income ◽  
Program Participation ◽  
Difference In Difference ◽  
Difference Estimator ◽  
Before And After ◽  
The Usa ◽  
Nationally Representative ◽  
The Difference ◽  
Time Frames

AbstractObjectiveTo assess patterns of food insecurity before and after initial receipt of Supplemental Security Income (SSI) benefits.DesignWe analysed data from a nationally representative sample. We estimated two difference-in-difference models comparing food insecurity patterns among eventual SSI recipients with patterns among eligible non-recipients during two time frames. The first model assessed changes in food insecurity immediately before SSI benefits were first received and the second model assessed changes in food insecurity after programme entry.Setting2008 panel of the Survey of Income and Program Participation.ParticipantsNon-institutionalized population of the USA.ResultsThe percentage of eventual SSI recipients experiencing food insecurity rose from 18 to 30 % in the year before programme entry, compared with a change from 17 to 18 % for eligible non-recipients. Adjusting for sociodemographic covariates, the difference-in-difference estimator for this comparison was statistically significant (P=0·01). Additionally, the percentage of recipients experiencing food insecurity fell from 28 % in the year before programme entry to 16 % in the year after entry, compared with a change from 16 to 17 % for eligible non-recipients. Adjusting for sociodemographic covariates, the difference-in-difference estimator for this comparison was marginally significant (P=0·07).ConclusionsFood insecurity rises prior to SSI entry but may be alleviated by programme benefits. Greater nutritional supports for SSI applicants awaiting decisions may reduce the burden of food insecurity in this population and improve health outcomes.

Does Mediation-Arbitration Reduce Arbitration Rates? Evidence from a Natural Experiment

ILR Review ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 211-235 ◽  
Author(s):  
Michele Campolieti ◽  
Chris Riddell
Keyword(s):  
Dispute Resolution ◽  
Natural Experiment ◽  
Difference In Difference ◽  
Canadian Province ◽  
Difference Estimator

To study the effect of the introduction of mediation-arbitration as a dispute resolution procedure on interest arbitration, the authors exploit a natural experiment in the arbitration institutions for police and firefighter sectors in the Canadian province of Ontario. They obtain estimates using a difference-in-difference estimator. Results show that the introduction of mediation-arbitration is significantly associated with increased use of arbitration by firefighters relative to the police. The article also draws on interviews with stakeholders to help explain the mechanisms that contribute to the increase in arbitration rates.

scholarly journals Synthetic controls with imperfect pretreatment fit

2021 ◽  
Vol 12 (4) ◽  
pp. 1197-1221 ◽  
Author(s):  
Bruno Ferman ◽  
Cristine Pinto
Keyword(s):  
Synthetic Control ◽  
Difference In Difference ◽  
Specification Test ◽  
Difference Estimator ◽  
Treatment Assignment ◽  
Practical Guidance ◽  
The Difference ◽  
Pre Treatment ◽  
Synthetic Controls ◽  
Theoretical Results

We analyze the properties of the Synthetic Control (SC) and related estimators when the pre‐treatment fit is imperfect. In this framework, we show that these estimators are generally biased if treatment assignment is correlated with unobserved confounders, even when the number of pre‐treatment periods goes to infinity. Still, we show that a demeaned version of the SC method can improve in terms of bias and variance relative to the difference‐in‐difference estimator. We also derive a specification test for the demeaned SC estimator in this setting with imperfect pre‐treatment fit. Given our theoretical results, we provide practical guidance for applied researchers on how to justify the use of such estimators in empirical applications.

scholarly journals Incidence of Kawasaki disease before and during the COVID-19 pandemic: a retrospective cohort study in Japan

2021 ◽  
Vol 5 (1) ◽  
pp. e001034
Author(s):  
Kyohei Iio ◽  
Kousaku Matsubara ◽  
Chisato Miyakoshi ◽  
Kunitaka Ota ◽  
Rika Yamaoka ◽  
...  
Keyword(s):  
Cohort Study ◽  
Kawasaki Disease ◽  
Infectious Diseases ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Bacterial Infections ◽  
Epidemiological Studies ◽  
Primary Objective ◽  
Temporal Association ◽  
Difference In Difference

BackgroundEpidemiological studies in Kawasaki disease (KD) have suggested infectious aetiology. During the COVID-19 pandemic, measures for mitigating SARS-CoV-2 transmission also suppress the circulation of other contagious microorganisms. The primary objective is to compare the number and incidence of KD before and during the COVID-19 pandemic in Japan, and the secondary objective is to investigate temporal association between the KD epidemiology and activities of SARS-CoV-2 and other viral and bacterial infections.MethodsA retrospective cohort study was conducted between 2016 and 2020 in Kobe, Japan. We collected information of hospitalised KD children in Kobe. Child population was identified through the resident registry system. Activity of COVID-19 and 11 other infectious diseases was derived from a public health monitoring system. Monthly change of KD incidence was analysed using a difference-in-difference regression model.ResultsThroughout the study period, 1027 KD children were identified. KD had begun to decline in April 2020, coinciding with the beginning of the COVID-19 pandemic. The number of KD cases (n=66) between April and December 2020 was 40% of the average in the same period in 2016–2019 (165/year). Annual KD incidence was 315, 300, 353, 347 and 188/100 000 children aged 0–4 years in 2016–2020, respectively. The difference-in-difference value of KD incidence was significantly reduced in the fourth quarter in 2020 (−15.8, 95% CI −28.0 to −3.5), compared with that in 2016–2019. Sentinel surveillance showed a marked decrease of all infectious diseases except exanthema subitum after the beginning of the COVID-19 pandemic. There were 86 COVID-19 cases aged <10 years and no KD children associated with COVID-19.ConclusionThis study showed that the number and incidence of KD was dramatically reduced during the COVID-19 pandemic in Japan. This change was temporally associated with decreased activities of various infectious diseases other than COVID-19, supporting the hypothesis of infection-triggered pathogenesis in KD.

Socio-economic differences in smoking among adolescents in a school-based smoking intervention: The X:IT II study

2021 ◽  
pp. 140349482110076
Author(s):  
Lotus S. Bast ◽  
Lisbeth Lund ◽  
Stine G. LauemØller ◽  
Simone G. Kjeld ◽  
Pernille Due ◽  
...  
Keyword(s):  
Preventive Intervention ◽  
First Year ◽  
Difference In Difference ◽  
Current Smoking ◽  
Smoking Intervention ◽  
School Time ◽  
School Based ◽  
Inequality In Health ◽  
Baseline Response

Aims: Socio-economic inequalities in health behaviour may be influenced by health interventions. We examined whether the X:IT II intervention, aiming at preventing smoking in adolescence, was equally effective among students from different occupational social classes (OSC). Methods: We used data from the multi-component school-based smoking preventive intervention X:IT II, targeting 13- to 15-year-olds in Denmark. The intervention was tested in 46 schools with 2307 eligible students at baseline (response rate=86.6%) and had three main intervention components: smoke-free school time, smoke-free curriculum and parental involvement. We used a difference-in-difference design and estimated the change in current smoking after the first year of implementation in high versus low OSC. Analyses were based on available cases ( N=1190) and imputation of missing data at follow-up ( N=1967). Results: We found that 1% of the students from high OSC and 4.9% from low OSC were smokers at baseline (imputed data), and 8.2% of the students from high OSC and 12.2% from low OSC were smokers at follow-up. Difference-in-difference estimates were close to zero, indicating no differential trajectory. Conclusions: As intended, the X:IT II intervention, designed to apply equally to students from all socio-economic groups, did not seem to create different trajectories in current smoking among adolescents in high and low socio-economic groups. To diminish social inequality in health, future studies should carefully consider the ability to affect all socio-economic groups equally, or even to appeal mainly to participants from lower socio-economic groups, as they are often the ones most in need of intervention.

Sign in / Sign up

Export Citation Format

Share Document