pdIsBalanced

Purpose

Checks if each group in a panel dataset covers the maximum time span.

Format

groupIsBalanced = pdIsBalanced(df[, groupvar, datevar])
Parameters:
  • df (Dataframe) – Contains long-form panel data with \(N_i \times T_i\) rows and K columns.
  • groupvar (String) – Optional, specifies the name of the variable used to identify group membership for panel observations. Defaults to the first categorical or string variable in the dataframe.
  • datevar (String) – Optional, specifies the name of the variable used to identify dates for panel observations. Defaults to the first date variable in the dataframe.
Returns:

groupIsBalanced (Dataframe) – Indicates whether each group in the panel dataset spans the full time range of the dataset. Each group is assigned a value of 1 if it covers the full time span, 0 otherwise.

Examples

// Load panel data and take the first 10 rows
pd = loadd(getGAUSSHome("examples/pd_ab.gdat"));
pd = pd[1:10,.];

print pd;

id             year              emp             wage
 1       1977-01-01        5.0409999        13.151600
 1       1978-01-01        5.5999999        12.301800
 1       1979-01-01        5.0149999        12.839500
 1       1980-01-01        4.7150002        13.803900
 1       1981-01-01        4.0929999        14.289700
 1       1982-01-01        3.1659999        14.868100
 1       1983-01-01        2.9360001        13.778400
 2       1977-01-01        71.319000        14.790900
 2       1978-01-01        70.642998        14.103600
 2       1979-01-01        70.917999        14.953400

// Check to see if each group is balanced
is_balanced = pdIsBalanced(pd);
print is_balanced;

The code above will return:

id         balanced
 1        1.0000000
 2        0.0000000

Remarks

This function takes long-form panel data. To transform wide data to long-form data see dfLonger().

This function assumes panel is sorted by group and date. Note that panel data can be sorted using pdSort().

This function evaluates whether each group in a panel dataset spans the maximum time range observed across all groups.

  • If groupvar is not provided, the function defaults to the first categorical or string variable in the dataframe.
  • If datevar is not provided, the function defaults to the first date variable in the dataframe.

The resulting dataframe contains each group and a corresponding indicator (1 or 0) to represent whether the group covers the full time span.

See also

pdAllBalanced(), pdbalance(), pdSummary()