STATISTICAL SOFTWARE
Stata Data Analysis Service
Reproducible Analysis for Research Teams
Our Stata data analysis service carries out panel, survey, survival and treatment-effect analysis in Stata, working from your .dta files and do-files, with a master do-file and logs provided where agreed so that every table can be rerun from the source data.
No Commitment Required
Strictly Confidential
In-House PhD-Level Statisticians
Fixed Project Fee
Same-Day Response
What Is Stata Used For in Research?
Stata is a commercial statistical package from StataCorp, widely used for econometric, panel, survey and epidemiological analysis. Researchers choose it for its panel, survey, survival, treatment-effect, multilevel and meta-analysis commands, and because a do-file records every step from the source data to the final table. That record makes a Stata analysis easy to audit, to extend and to submit with a replication request. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, provides a Stata data analysis service in which an in-house PhD-level statistician carries out the agreed analysis in Stata, working from your files and documenting each step so that you can rerun it.
WHEN TO ENGAGE
Four Points at Which Researchers Bring Us a Stata Project
What a Stata statistician is asked to do depends on what is already in place: a finished dataset, a stalled setup, existing do-files or a replication request.
Model Ready to Run in Stata Your data are in Stata and the research question and model are decided, and you need the analysis carried out, checked and reported with effect estimates and confidence intervals.
Setup That Will Not Behave A panel will not declare, a merge returns more rows than expected or survey estimates look wrong, and the cause has to be found in the data structure before any model is trusted.
Do-Files to Check or Extend A coauthor's or an earlier project's do-files need to be corrected or extended, and Stata do-file consulting here means working from what the files do, not from the output alone.
Replication or Reviewer Request A journal, funder or reviewer asks for code that reproduces the tables from the source data, so the analysis has to be rerun, documented and organized under a master do-file.
ANALYSES IN STATA
Analyses Carried Out in Stata for Your Data Structure
Each analysis is chosen for the outcome and the structure of your data, and its card links to the method page where the choice between estimators is explained.
Panel Data Analysis (Fixed & Random Effects)
Stata panel data analysis starts with a unique entity and time identifier declared with xtset, then fixed or random effects with errors clustered on the panel.
Difference-in-Differences (DiD)
Treatment timing and the comparison group are set from dated data, errors are clustered at the level where treatment is assigned, and pre-trends are examined before an effect is reported.
Instrumental Variable Analysis
The first stage is checked for instrument strength and two-stage estimates are shown beside OLS, while the exclusion restriction is argued from the design, not tested.
Linear Mixed Models (Multilevel Modeling)
Pupils within schools or visits within patients are fitted in mixed with random intercepts, and random slopes where the design supports them, once the nesting is confirmed from the identifiers.
Survival Analysis
Time-to-event data are declared with stset, with time origin, event and censoring defined, then analyzed with Kaplan-Meier curves, Cox models and proportional-hazards checks.
Logistic Regression
Binary outcomes are modeled with logit, and results are read as odds ratios and as predictive margins or marginal effects on the probability scale, with the covariate set limited by the number of events.
COMMON STATA ISSUES
Where Stata Analyses Go Wrong Before the Model
Most Stata errors come from how the data were prepared, not from the model, and many produce no error message, so each check below is made before an estimate is reported.
Duplicate IDs Before a Merge A merge on an identifier that is not unique multiplies rows or, with m:m, pairs observations by position. Uniqueness is verified and the match result inspected before analysis.
Repeated Panel-Time Values A panel needs one row per entity and period, so repeated time values are traced to duplicate records or a wrong time variable instead of being dropped to make xtset run.
Missing Values in Comparisons Stata treats a missing numeric value as larger than any number, so x > 0 includes missing observations. Extended missing codes are recoded deliberately and conditions exclude them.
Strings, Encoding and Labels Categorical variables stored as strings are encoded with labels that match the codebook and entered with factor-variable notation, so category codes never act as a continuous predictor.
Survey Design Declared Weights, strata and primary sampling units are declared with svyset, and a subgroup is analyzed with subpop, because dropping the other cases misstates the standard errors.
Cluster Level and Few Clusters Standard errors are clustered at the level where observations are correlated, and with few clusters they are checked with a wild cluster bootstrap, because the usual clustered errors are then too small.
DELIVERABLES
What You Receive From a Stata Analysis
The files follow a reproducible Stata project, agreed in the scope and provided where applicable, so that you can rebuild every reported number yourself.
Master Do-File A master do-file that calls numbered do-files for cleaning, analysis and tables, so the results can be rebuilt from the source data in one run.
Log Files Log files that record the commands and the output of every run, kept with the do-files as the audit trail behind each estimate in the tables and figures.
Cleaned, Labeled Dataset A cleaned .dta file with variable and value labels, plus a codebook of the recoding decisions and every missing-value code used.
Tables and Figures Publication-ready tables and figures in Word, Excel or LaTeX as agreed, with effect estimates, confidence intervals and the sample size behind each.
Statistical Interpretation Each estimate is explained within what the design supports, with its statistical limitations stated plainly.
Version and Packages The Stata version and any user-written packages are recorded, so that a coauthor or reviewer can reproduce the analysis with the same setup.
OTHER PLATFORMS
When Another Platform May Be More Appropriate
Stata suits many projects, but the software follows the method, and in some situations another platform serves the research question or the team better.
ILLUSTRATIVE EXAMPLE
How a Stata Analysis May Look in Practice
An illustration of how a panel built from separate extracts moves from a merge to a result that can be rerun.
ILLUSTRATIVE EXAMPLE · HOSPITAL FINANCE POLICY RESEARCH · UNITED STATES
A health policy research institute wanted to estimate how hospital operating cost per discharge moves with the share of Medicaid patients, using annual extracts from two sources for the same hospitals.
The unit of analysis was fixed as the hospital-year, and the model, hospital fixed effects with errors clustered by hospital, was chosen before any estimate was inspected. The first attempt to declare the panel stopped on repeated years: after a merger, two hospitals had been reported under one identifier, so that identifier carried two records for the same year. The merge key was checked for uniqueness in both extracts, the duplicates were traced to source and resolved by a documented rule, and only then was the panel declared. Missing cost values, coded as extended missing in one extract, were excluded explicitly from every comparison, and the whole analysis ran from one master do-file.
Outcome: The institute received the fixed-effects estimate with its 95% confidence interval, the log files, a cleaned and labeled .dta file and a master do-file that rebuilds every table from the two extracts.
This example does not describe a real client or project. We never share details of actual client work, in line with the confidentiality we promise every researcher. This illustrative example is included to show the type, scope, and standard of work involved in this kind of analysis.
RESEARCH DISCIPLINES
Research Fields Where Stata Is Common
Stata is often the platform of choice in economics, health policy and epidemiology, and the same setup and reproducibility questions arise in every field that analyzes panels, surveys or cohorts.
HOW WE ASSESS YOUR PROJECT
We Review Your Actual Research
Your assessment is based on a review of your actual research materials and analytical requirements, not a generic project category.
You Submit Your Project Details
Share whatever is available at the current stage, such as the research aim, protocol or proposal, dataset, variable list, manuscript or statistical requirements.
We Review Your Research and Define the Scope
Your statistically trained Research Coordinator reviews the materials to understand the study design, research questions, data structure, analytical requirements and expected deliverables. If clarification is needed, additional documents or information can be requested before the assessment is finalized.
Your Analysis Is Completed and Delivered
Once the scope and fixed project fee are agreed, the in-house statistician completes the work and the Research Coordinator remains the communication point through delivery, with the analysis, deliverables and timeline as agreed.
RESEARCHER VOICE
What Researchers Say
Feedback from a health economist on duplicate IDs, panel setup and a reproducible workflow built from the files already in hand.
“Our issue with Stata was not the interface itself; it was duplicate IDs and repeated time values causing problems in merges and panel setup. They worked directly with the files we already had and left us with a much cleaner, reproducible workflow rather than just screenshots of output.”
Statistical Support Within Your Research OnlineSPSS provides the agreed methodological, analytical and statistical reporting support, including the Stata files described in the scope. The researcher or research team retains the scientific question, substantive interpretation, conclusions and overall responsibility for the research.
FREQUENTLY ASKED QUESTIONS
Questions About Stata Analysis for Research
Short answers to what researchers ask before sharing a Stata project, from the analyses we carry out and existing do-files to reproducibility, platform choice and confidentiality.
Which analyses do you carry out in Stata?
Stata statistical analysis at OnlineSPSS covers the models researchers most often run in it: panel and fixed-effects models, difference-in-differences, instrumental variables, mixed models, survival analysis, logistic regression and survey-weighted estimation. The choice follows your research question and data structure, and it is confirmed during the assessment.
Can you work from my existing do-files and .dta files, or only from output?
We work from the files themselves: your .dta datasets, do-files and logs, not from output alone. Existing code is read before it is extended, and a completed analysis can be checked through Independent Statistical Review, with a statement of what stands and what should change. Do-files drafted by hand, from menus or with an AI tool are reviewed the same way.
Can you make my analysis reproducible with a master do-file and logs?
Yes, within the agreed scope. The test is a clean run: the master do-file is run from an empty Stata session on the source data, and the tables it produces are compared with those in the manuscript. A journal’s own data and code policy decides what must be submitted, and where the source data cannot be shared, the code is organized so that it runs once access is granted.
Should my project stay in Stata or move to another platform?
Usually it should stay in Stata. Translating a finished project means rewriting every command and rechecking every estimate, so a move is worth it only when a required estimator is missing or poorly supported in Stata, which the assessment checks against your model, or when coauthors must rerun the code in another platform.
How do you protect my research data and confidentiality?
Your .dta datasets, do-files and logs are handled confidentially, and project information is not published. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You share your research question, design and relevant materials, such as the dataset and any do-files, and a statistically trained Research Coordinator reviews the request and responds the same day. The analysis, deliverables, timeline and one fixed project fee are then confirmed before any work begins, so the timeline follows from the agreed scope.
Still have a question? Find more answers in our full FAQ.
NEXT STEP
Discuss Your
Stata Analysis With Us
Share your research question, data and any existing do-files or logs, and the models you have in mind. We check the files and confirm the Stata setup before any work begins.
No Commitment Required
Strictly Confidential
Fixed Project Fee
In-House PhD-Level Statisticians
Same-Day Response
Serving Researchers Since 2014