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Data Management Pillar

Import, types, joins, reshape, dates, and key validation patterns.

27 guides in this category

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merge in Stata: 1:1, m:1, 1:m with Match Audits

Use merge stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

import excel in Stata: Clean Types, Headers, Ranges, and Dates

Use import excel stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

append in Stata: Stack Datasets Safely with Variable Alignment Checks

Use append stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

Missing Values in Stata: ., .a-.z, and Safe Recode Rules

Use missing values stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

bysort in Stata: Reusable Within-Group Transform Patterns

Use bysort stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

Duplicates in Stata: report/list/drop with an Audit Checklist

Use duplicates drop stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

tostring in Stata: Convert Without Breaking IDs and Merges

Use tostring stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

recode in Stata: Safer Category Edits and Missing Handling

Use recode stata in Stata with full runnable code, realistic panel variables, and QA checks before downstream estimation.

Common Tasks

merge in Stata: 1:1, m:1, 1:m with Match Audits

reshape in Stata: Wide to Long and Back with Repeatable Patterns

import excel in Stata: Clean Types, Headers, Ranges, and Dates

append in Stata: Stack Datasets Safely with Variable Alignment Checks

collapse in Stata: Group Summaries Without Losing Design Integrity

egen in Stata: Group IDs, Totals, Ranks, and Practical Cookbook Patterns

encode vs egen group() in Stata: Correct Category IDs for Modeling

Stata Dates: daily(), %td, %tm, and Import Trap Fixes

Missing Values in Stata: ., .a-.z, and Safe Recode Rules

bysort in Stata: Reusable Within-Group Transform Patterns

Duplicates in Stata: report/list/drop with an Audit Checklist

tostring in Stata: Convert Without Breaking IDs and Merges

recode in Stata: Safer Category Edits and Missing Handling

Value Labels in Stata: label define, label values, and Label Hygiene

Troubleshooting

destring and real() in Stata: Convert String Numbers Safely

Why merge m:m in Stata Is Dangerous and What to Do Instead

reshape long in Stata: Fix i/j Errors and Duplicate Keys

reshape wide in Stata: Stubs, Suffixes, and Sparse Panels

Stata Error "string variables not allowed": Causes and Fixes

Stata type mismatch r(109): A Diagnostic Workflow

Stata variable not found r(111): Why It Happens and Prevention

Stata no observations r(2000): Filters, Merges, and Missingness

Command Index

append in Stata: Stack Datasets Safely with Variable Alignment Checks

bysort in Stata: Reusable Within-Group Transform Patterns

collapse in Stata: Group Summaries Without Losing Design Integrity

contract in Stata: Frequency Tables You Can Merge Back

Duplicates in Stata: report/list/drop with an Audit Checklist

egen in Stata: Group IDs, Totals, Ranks, and Practical Cookbook Patterns

encode vs egen group() in Stata: Correct Category IDs for Modeling

import excel in Stata: Clean Types, Headers, Ranges, and Dates

isid in Stata: Enforce Key Uniqueness and Repair Failures

joinby in Stata: Many-to-Many Matching with Explicit Audits

keep/drop in Stata: Subset Data Without Accidental Loss

Value Labels in Stata: label define, label values, and Label Hygiene

merge in Stata: 1:1, m:1, 1:m with Match Audits

Missing Values in Stata: ., .a-.z, and Safe Recode Rules

Range Joins in Stata: Match Rows Within Date and Value Intervals

recode in Stata: Safer Category Edits and Missing Handling

reshape in Stata: Wide to Long and Back with Repeatable Patterns

Sorting in Stata: sort, gsort, stable, and Tie Handling

Stata Dates: daily(), %td, %tm, and Import Trap Fixes

summarize, detail in Stata: Percentiles, Skewness, and Checks

tabulate in Stata: One-Way, Two-Way, Missing, and Percentages

tostring in Stata: Convert Without Breaking IDs and Merges

tsset in Stata: Time-Series Setup, Formats, and Duplicate Times

xtset in Stata: Panel IDs, Time Variables, and Gap Pitfalls

All Guides in This Category

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merge in Stata: 1:1, m:1, 1:m with Match Audits

reshape in Stata: Wide to Long and Back with Repeatable Patterns

import excel in Stata: Clean Types, Headers, Ranges, and Dates

append in Stata: Stack Datasets Safely with Variable Alignment Checks

collapse in Stata: Group Summaries Without Losing Design Integrity

egen in Stata: Group IDs, Totals, Ranks, and Practical Cookbook Patterns

encode vs egen group() in Stata: Correct Category IDs for Modeling

Stata Dates: daily(), %td, %tm, and Import Trap Fixes

Missing Values in Stata: ., .a-.z, and Safe Recode Rules

bysort in Stata: Reusable Within-Group Transform Patterns

Duplicates in Stata: report/list/drop with an Audit Checklist

tostring in Stata: Convert Without Breaking IDs and Merges

recode in Stata: Safer Category Edits and Missing Handling

Value Labels in Stata: label define, label values, and Label Hygiene

keep/drop in Stata: Subset Data Without Accidental Loss

joinby in Stata: Many-to-Many Matching with Explicit Audits

Range Joins in Stata: Match Rows Within Date and Value Intervals

merge keepusing() and keep(match) in Stata: Cleaner Joins

xtset in Stata: Panel IDs, Time Variables, and Gap Pitfalls

tsset in Stata: Time-Series Setup, Formats, and Duplicate Times

Sorting in Stata: sort, gsort, stable, and Tie Handling

Unique IDs in Stata: egen group(), isid, and Key Discipline

isid in Stata: Enforce Key Uniqueness and Repair Failures

contract in Stata: Frequency Tables You Can Merge Back

tabulate in Stata: One-Way, Two-Way, Missing, and Percentages

summarize, detail in Stata: Percentiles, Skewness, and Checks

import delimited in Stata: CSV Imports Without Type Breaks