This file describes the content of the product life cycles database, that accompanies the following paper (please reference when using this data):

"Product Life Cycles in Corporate Finance", by Gerard Hoberg and Vojislav Maksimovic, Review of Financial Studies forthcoming.
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3182158


 Note that the following working paper also uses this data
"Life Cycles of Firm Disclosures", by AJ Chen, Gerard Hoberg and Vojislav Maksimovic
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3703931


****** Please read the data section of the paper for complete details regarding how the variables are computed.  ********
****** This file is best read in a text editor with word wrap turned on.  *******

We note some basic details about the data here (see paper for full detail).  First, the data is indexed by Compustat gvkey and by year, so they can be merged into existing databases easily.  The year refers to the calendar year in which the given firm's fiscal year ends.  The data is not lagged. If you wish to have lagged data, the researcher must do this on their own.  Also note that this data has been extended since the paper was written and now covers the years 1997 to 2019.  In order to be in this database, the firm-year must be in the Compustat database and must also have a 10-K filed on the SEC Edgar website (in which case it will also have observations in the metaHeuristica database).  We do not further screen or filter the data here as that allows other researchers maximum flexibility to filter or screen the data as is appropriate for their own research.

We thank Christopher Ball of metaHeuristica for providing us with text processing capabilities for SEC filings stored in a high speed database for fast and precise queries.  Please see https://www.metaheuristica.com/ for information about this resource.


*** There following variables are included in the database in addition to the key gvkey and year identifiers ***
life1 to life4: The four life cycle stages used in the above paper "Product Life Cycles in Corporate Finance".  These four stages sum to unity.  This makes them ideal for running conditional regressions such as was done in the above mentioned paper for investment-Q models.