*! version 1.0.0 21 Apr 2026

Title

c25tom5 -- Recode MTUS Core 25 activity categories into 5 broad activity groups

Syntax

c25tom5 varname, gen(newvar)

varname numeric variable coded in the MTUS Core 25 activity scheme

gen(newvar) name of the new recoded variable to create; required

Description

c25tom5 recodes an activity variable from the MTUS Core 25 scheme into a simpler variable with 5 broad activity groups.

This is useful when a more aggregated classification is sufficient for analysis, graphs, or descriptive summaries.

The command creates a new variable specified in gen() and assigns it one of five categories:

1 = personal

2 = paid work

3 = unpaid work

4 = leisure

5 = travel

A value label is also attached to the generated variable.

Arguments

varname must be a numeric variable coded in the MTUS Core 25 activity scheme.

gen(newvar) specifies the name of the new variable to be created.

How categories are recoded

The mapping used by c25tom5 is:

New category

1 personal original codes 1, 2, 3

2 paid work original codes 4, 5, 17

3 unpaid work original codes 6, 7, 8, 9, 10, 11, 12, 13, 14

4 leisure original codes 15, 16, 19, 20, 21, 22, 23, 24

5 travel original code 18

Original code 25 is recoded to system missing.

Extended missing values .a, .b, .c, and .d are also recoded to system missing.

What the command creates

c25tom5 creates a new numeric variable named in gen().

The new variable receives the following value label:

1 -- personal

2 -- paid work

3 -- unpaid work

4 -- leisure

5 -- travel

Examples

Example 1: Recode a Core 25 activity variable

. c25tom5 c25, gen(c5)

This creates c5, a five-category version of c25.

Example 2: Tabulate the new groups

. c25tom5 activity25, gen(activity5)

. tab activity5

Remarks

1. Input must be numeric

The command requires a numeric input variable. If your activity variable is stored as a string, it must be converted before using c25tom5.

2. The original variable is not modified

c25tom5 leaves the source variable unchanged and creates a new recoded variable.

3. Missing and residual categories

Code 25 and extended missing values are recoded to system missing in the generated variable.

Stored results

c25tom5 does not store results in r() or e(). Results are returned through the created variable.

Author

Juana Lamote de Grignon-Pérez

Centre for Time Use Research (CTUR)

Also see

Other small recode utilities in the same toolkit may provide similar crosswalks for alternative activity classifications.