Difference-in-Differences Parallel Trend Calculator

Compute the DiD estimator as (post-pre treatment group) − (post-pre control group). Assess the parallel trends assumption by testing pre-treatment trend differences between groups.

 
0
Physical Constants Reference
ConstantSymbolValue
Speed of lightc2.99792458×10⁸
Planck's constanth6.62607015×10⁻³‴
Boltzmann constant1.380649×10⁻²³
Avogadro's numberNₐ6.02214076×10²³
Gravitational constantG6.6743×10⁻¹¹
Gas constantR8.31446
Elementary chargee1.602176634×10⁻¹⁹
Electron massmₑ9.1093837015×10⁻³¹
Proton massmₚ1.67262192369×10⁻²⁷
Fine-structure constantα7.2973525693×10⁻³
Advertisement

How to Use

Enter the values for the patient or scenario you are assessing. Compute the DiD estimator as (post-pre treatment group) − (post-pre control group). Assess the parallel trends assumption by testing pre-treatment trend differences between groups. Use the did estimator result to inform your clinical assessment.

Frequently Asked Questions