CSHAPES DATASET OF HISTORICAL COUNTRY BOUNDARIES 
http://nils.weidmann.ws/projects/cshapes

Nils B. Weidmann (nils.weidmann@googlemail.com)
Doreen Kuse (doreen.kuse@googlemail.com)
Kristian Skrede Gleditsch (ksg@essex.ac.uk)

This version: 0.2-3 (February 24, 2010)

Dataset format
--------------

ESRI shapefile, WGS84 reference system, longitude/latitude coordinates.


General description
-------------------

This is a GIS dataset of country boundaries, incorporating changes in the 
period 1946-2008. The list of states is compatible with the 
"Correlates of War" system membership list, version 2008.1, 
and the Gleditsch and Ward (1999) list of independent states. 
The dataset provides information about the core territories of 
the given states, and excludes colonies and other dependent 
territories. The changing boundaries of the international system 
are represented in the dataset by coding a "lifetime" 
for each polygon, i.e. a start and end date between which the polygon is valid.


Description of the variables in the dataset
-------------------------------------------

* CNTRY_NAME: the country name
* AREA: The polygon area in square kilometers, computed using an 
	Eckert VI projection
* CAPNAME: The name of the country capital
* CAPLONG, CAPLAT: Longitude/latitude of the capital, in decimal degrees
* FEATUREID: A unique identifier for each polygon
* COWCODE: Correlates of War numeric identifier code
* COWSYEAR, COWSMONTH, COWSDAY: Start date of the polygon,
	based on Correlates of War system list
* COWEYEAR, COWEMONTH, COWEDAY: End date of the polygon,
	based on Correlates of War system list
* GWCODE: Gleditsch&Ward (1999) numeric identifier code
* GWSYEAR, GWSMONTH, GWSDAY: Start date of the polygon,
	based on Gleditsch and Ward list of independent states  
* GWEYEAR, GWEMONTH, GWEDAY: End date of the polygon,
	based on Gleditsch and Ward list of independent states
* ISONAME: Country name according to ISO 3166 standard (Note: ISO 3166
	applies only to polygons active during and after 1974).
* ISO1NUM: ISO 3166-1 numerical country codes (0 if not applicable)
* ISO1AL2: ISO 3166-1 Alpha2 two-character country codes
* ISO1AL3: ISO 3166-1 Alpha3 three-character country codes


References
----------
Correlates of War Project. 2008. "State System Membership List, v2008.1." 
Online, http://correlatesofwar.org.

Gleditsch, Kristian S. & Michael D. Ward. 1999. "Interstate System Membership: 
A Revised List of the Independent States since 1816." International Interactions 25: 393-413. 
Online, http://privatewww.essex.ac.uk/~ksg/statelist.html.

ISO 3166 Maintenance agency. 2008. "ISO 3166 code lists". 
Online, http://www.iso.org/iso/country_codes/iso_3166_code_lists.htm.


Citation
--------
When using CShapes, please cite 

Weidmann, Nils B., Doreen Kuse, and Kristian Skrede Gleditsch. 
"The Geography of the International System: The CShapes Dataset." 
International Interactions 36, no. 1 (2010).


License
-------
The CShapes dataset was created using the country layer from the ESRI "Data and Maps" 
collection (http://www.esri.com/data/data-maps/index.html), version 2006. The original 
dataset is (C) 2006 Environmental Systems Research Institute, Inc. 
Modification and redistribution with permission from ESRI Inc.


Acknowledgements
----------------
We gratefully acknowledge help and comments from the following people:
Håvard Hegre, Luc Girardin, Håvard Strand, Jan Ketil Rød, Andreas Forø Tollefsen, 
Kaspar Kundert (ESRI Switzerland), Chad Clay, Lars-Erik Cederman. 
