GDPt1GDPt1

GDPt1GDPt1 is not a standard economic indicator. In published literature and official statistics, the string does not refer to a well-defined measure, but is more often a label or artifact you may encounter in datasets or model specifications. A more common notation is GDPt-1 (GDP at time t minus one, a lagged value). When the concatenated form GDPt1GDPt1 appears, two plausible explanations exist: it may be a data formatting artifact resulting from duplicating a column label during import or export; or it may intentionally reflect a modeling choice that uses two copies or a derived term based on the lagged GDP variable.

Possible interpretations include:

- A duplication of the lagged GDP variable, used to align data for a multi-variable panel or time-series specification.

- An interaction or nonlinear term involving the lagged GDP, such as an equation where GDPt-1 is squared or multiplied by itself, although this would typically be labeled more clearly (e.g., GDPt-1 squared).

- A mislabeling issue where GDPt-1 has been concatenated with itself by error.

Practical guidance:

- Check the data dictionary and variable metadata to determine the intended meaning.

- Inspect the data columns to see whether GDPt1 and GDPt1 are duplicates, or whether the term represents a transformed variable.

- Rename and document the variable clearly, and avoid using ambiguous labels in analyses.

Sources for GDP definitions and lag notation include national accounts,

IMF, World Bank, and standard econometrics references.