The document provides information on the format and structure of pre-made panel datasets. It notes that all panel datasets contain a variable called "panel" that identifies panel observations. Where possible, variables from older rounds are matched to the newest round. Some variables could not be matched and remain in their original form. Due to survey changes, not all variables can be matched across years. Users are advised to review questionnaires from all years before analysis. Some monetary variables are converted to a local currency unit using exchange rates. The panel structure shows firms interviewed in 2013 only, 2016 only, or both years, with unique identifiers to match firms across years.

1. Notes on Panel Dataset
The pre-made panel datasets available for download have a common format which can be
summarized as follows:
 All panel datasets contain a variable "panel" that allows easy identification of panel
observations
 Wherever possible variables in the older rounds have been matched to variables in the
newest round.
 Any variables that could not be matched are retained in their original form.
 Due to methodological changes and evolution of the survey instrument it is not possible
to match all variables in the datasets.
 It is recommended that users thoroughly familiarize themselves with the questionnaires
from each of the years contained in the dataset before proceeding with analysis.
 For some monetary unit variables (in US currency) in 2002 and 2005 surveys, these
variables are converted into the local currency units (LCU) using the market, period
average, exchange rates. The source of the exchange rates is from the International
Financial Statistics (IFS - IMF) websites.
To understand more about the panel structure, please type in Stata: tab panel year
Panel: Firm |
interviewed in these | Year of survey
years | 2013 2016 | Total
----------------------+----------------------+----------
2016 only | 0 242 | 242
2013 only | 341 0 | 341
2013 and 2016 | 131 131 | 262
----------------------+----------------------+----------
Total | 472 373 | 845
Note: The variable idstd2016 contains a unique identifier for firms that have been interviewed in
2016. The variable idstd2013 contains a unique identifier for firms that have been interviewed in
2013. Firms that have been interviewed in both years have the same idstd2016 in both 2013 and
2016 interviews, which can be used to match firms across years. Firms interviewed in 2013 that
are missing an idstd2016 have been screened for eligibility in 2016, but they have NOT been
interviewed in 2016. Their eligibility status in 2016 is reported in the variable eligibility2016.