Cite data for the same reasons you cite other sources of information, such as articles or books. Data citation helps by:
Sources: Why Cite Data? from DataCite, Data Citations from ICPSR, Quick Guide to Data Citation from the International Association for Social Science Information Services and Technology (IASSIST), Why and How Should I Cite Data? from ICPSR.
Citing data isn't very complicated. Each citation should include the basic elements that allow research data to be discovered:
Some dataset sources, such as ICPSR, will provide you with a citation for a dataset. Others may give you more general information, such as where to find the elements needed for a citation.
Arrange the basic elements using the order and punctuation specified by the style guide you have been asked to use. Be sure to include as many elements as needed to precisely identify the dataset you have used. It is always better to provide more information rather than less.
Sources: Why Cite Data? from DataCite, Data Citations from ICPSR, Quick Guide to Data Citation from the International Association for Social Science Information Services and Technology (IASSIST), Why and How Should I Cite Data? from ICPSR
ICPSR datasets have citations available in the "At a Glance" section of the project description. These citations are dynamically generated from other metadata fields and follow this format: Principal Investigator(s). Title. Place-of-Distribution and Distributor, Date-of-Distribution. DOI.
Some examples of ICPSR data citations include:
American National Election Studies, University of Michigan, and Stanford University. ANES 2016 Time Series Study. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2017-09-19. https://doi.org/10.3886/ICPSR36824.v2
Elliot, Patrick. Three Generations Combined, 1965-1997. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2007-03-23. https://doi.org/10.3886/ICPSR04532.v1
ABC News. ABC News Discovery Space Poll, July 1997. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2007-06-12. https://doi.org/10.3886/ICPSR02500.v1
Sources: Why Cite Data? from DataCite, Data Citations from ICPSR, Quick Guide to Data Citation from the International Association for Social Science Information Services and Technology (IASSIST), Why and How Should I Cite Data? from ICPSR