To transform cross-section data to panel data

[Mayuko Kimura]

Dear Sir/Madam,

I am doing the research on commercial jet aircraft, and each sample has "lease start date" and "lease end date". Using these data, I would like to transform the dataset into panel data. Is there any command which can be used for?

ID	Type	Lease End	Lease Start
A	737-800	2022/12/31	2017/1/1
B	777-300ER
C	A320

　↓

ID	Type	Lease End	Lease Start	Year	Lease
A	737-800	2022/12/31	2017/1/1	2017	1
				2018	1
				2019	1
				2020	1
				2021	1
				2022	1
				2023	0

Best regards,
Mayuko Kimura

[Clyde Schechter]

So the first thing is to import the data into Stata and create proper Stata internal format date variables for Lease End and Lease Start. Once you have done that:

gen start_year = year(lease_start)
gen end_year = year(lease_end)

expand end_year - start_year + 2
by id, sort: gen year = start_year + _n - 1
by id (year), sort: gen lease = (_n < _N)

drop *_year

In the future, when showing data examples, please use the -dataex- command to do so. If you are running version 15.1 or a fully updated version 14.2, it is already part of your official Stata installation. If not, run -ssc install dataex- to get it. Either way, run -help dataex- to read the simple instructions for using it. -dataex- will save you time; it is easier and quicker than typing out tables. It includes complete information about aspects of the data that are often critical to answering your question but cannot be seen from tabular displays or screenshots. It also makes it possible for those who want to help you to create a faithful representation of your example to try out their code, which in turn makes it more likely that their answer will actually work in your data.

When asking for help with code, always show example data. When showing example data, always use -dataex-.

[Mayuko Kimura]

Dear Clyde,

Thank you very much for your kind help. I could transform the data successfully.
Noted to use -dataex- for my future posts.

Many thanks,
Mayuko