Excessive fields in biblatex chicago author-date style

I am trying to produce simple latex document with bibliography, generated from Zotero (export in biblatex, "ISO Western 8859-1" encoding). For bibliography I use biblatex with biber as backend and try to implement biblatex-chicago authordate style.

Here is the code:

\documentclass[11pt]{article}
\usepackage[hmargin=3cm,vmargin=3cm]{geometry}
\usepackage{setspace}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{booktabs}
\usepackage{graphicx}
\usepackage{enumitem}
\usepackage{cancel}
\usepackage{soul}
\usepackage[authordate,backend=biber,bookpages=false,doi=false,isbn=false,url=false]                        {biblatex-chicago}
\usepackage{hyperref}
\hypersetup{pdfstartview={XYZ null null 1.25}}
\singlespace
\AtEveryBibitem{\clearlist{language}}

\begin{document}

\title{\textbf{Example}\\\emph{Example}: Example}
\author{Example}
\date{}

\maketitle
\section{Example}

Example \parencite{benoit_institutional_2004}. Example by \textcite{benoit_models_2004}.

Examples \parencites{myagkov_forensics_2009}{enikolopov_field_2013}. Examples         \parencites{gandhi_cooperation_2006}{gandhi_authoritarian_2007} especially example  \parencite{levitsky_rise_2002}. \citeauthor{simpser_why_2013}'s (\citeyear{simpser_why_2013}) example.

According to \citeauthor{benoit_institutional_2004}'s (\citeyear{benoit_institutional_2004}) example.

\printbibliography

\end{document}


Here is the .bib database:

@article{enikolopov_field_2013,
title = {Field experiment estimate of electoral fraud in Russian parliamentary elections},
volume = {110},
issn = {0027-8424, 1091-6490},
url = {http://www.pnas.org/content/110/2/448},
doi = {10.1073/pnas.1206770110},
language = {en},
issue = {2},
pages = {448-452},
journaltitle = {Proceedings of the National Academy of Sciences},
shortjournal = {{PNAS}},
author = {Enikolopov, Ruben and Korovkin, Vasily and Petrova, Maria and Sonin, Konstantin and Zakharov, Alexei},
urldate = {2013-10-28},
date = {2013},
keywords = {authoritarian politics, nondemocratic government}
}

@book{simpser_why_2013,
title = {Why governments and parties manipulate elections theory, practice, and implications},
isbn = {9781107306882  1107306884  9781107314634  1107314631  9781139343824  1139343823},
language = {English},
publisher = {Cambridge University Press},
author = {Simpser, Alberto},
date = {2013}
}

@book{myagkov_forensics_2009,
title = {The Forensics of Election Fraud: Russia and Ukraine},
isbn = {9780521764704},
shorttitle = {The Forensics of Election Fraud},
language = {en},
publisher = {Cambridge University Press},
author = {Myagkov, Mikhail and Ordeshook, Peter C. and Shakin, Dimitri},
date = {2009},
keywords = {Law / Forensic Science, Political Science / Comparative Politics, Political Science / General, Political Science / Political Process / Elections, Reference / Research}
}

@article{gandhi_cooperation_2006,
title = {Cooperation, Cooptation, and Rebellion Under Dictatorships},
volume = {18},
issn = {1468-0343},
url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1468-0343.2006.00160.x/abstract},
doi = {10.1111/j.1468-0343.2006.00160.x},
language = {en},
issue = {1},
pages = {1-26},
journaltitle = {Economics \& Politics},
author = {Gandhi, Jennifer and Przeworski, Adam},
urldate = {2013-10-28},
date = {2006}
}

@article{gandhi_authoritarian_2007,
title = {Authoritarian Institutions and the Survival of Autocrats},
volume = {40},
issn = {0010-4140, 1552-3829},
url = {http://cps.sagepub.com/content/40/11/1279},
doi = {10.1177/0010414007305817},
language = {en},
issue = {11},
pages = {1279-1301},
journaltitle = {Comparative Political Studies},
shortjournal = {Comparative Political Studies},
author = {Gandhi, Jennifer and Przeworski, Adam},
urldate = {2013-10-28},
date = {2007-11-01},
keywords = {Authoritarianism, autocracy, Dictatorship, leaders, survival}
}

@article{benoit_institutional_2004,
title = {Institutional Change and Persistence: The Evolution of Poland's Electoral System, 1989-2001},
volume = {66},
issn = {1468-2508},
url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1468-2508.2004.00157.x/abstract},
doi = {10.1111/j.1468-2508.2004.00157.x},
shorttitle = {Institutional Change and Persistence},
language = {en},
issue = {2},
pages = {396-427},
journaltitle = {Journal of Politics},
author = {Benoit, Kenneth and Hayden, Jacqueline},
urldate = {2013-10-28},
date = {2004}
}

@article{benoit_models_2004,
title = {Models of electoral system change},
volume = {23},
issn = {0261-3794},
url = {http://www.sciencedirect.com/science/article/pii/S0261379403000209},
doi = {10.1016/S0261-3794(03)00020-9},
issue = {3},
pages = {363-389},
journaltitle = {Electoral Studies},
shortjournal = {Electoral Studies},
author = {Benoit, Kenneth},
urldate = {2013-10-28},
date = {2004-09},
keywords = {Electoral systems, Institutional change, Institutional origins}
}

@article{benoit_electoral_2007,
title = {Electoral Laws as Political Consequences: Explaining the Origins and Change of Electoral Institutions},
volume = {10},
issn = {1094-2939, 1545-1577},
url = {http://www.annualreviews.org/eprint/Ha2R36zNUCxGX2yWZGwX/full/10.1146/annurev.polisci.10.072805.101608},
doi = {10.1146/annurev.polisci.10.072805.101608},
shorttitle = {Electoral Laws as Political Consequences},
issue = {1},
pages = {363-390},
journaltitle = {Annual Review of Political Science},
author = {Benoit, Kenneth},
urldate = {2013-10-28},
date = {2007-06}
}

@article{levitsky_rise_2002,
title = {The Rise of Competitive Authoritarianism},
volume = {13},
issn = {1086-3214},
doi = {10.1353/jod.2002.0026},
issue = {2},
pages = {51-65},
journaltitle = {Journal of Democracy},
author = {Levitsky, Steven and Way, Lucan},
urldate = {2013-10-28},
date = {2002}
}


Here is the output:

The main problem I have is excessive fields. For example, in the output above I have "Accessed date" [from urldate filed in .bib file], and I cannot eliminate it, say, in the same way I eliminated language of publication. Neither of suggestions from Guidelines for customizing biblatex styles can do the trick:

    \AtEveryBibitem{\clearname{urldate}}
\AtEveryBibitem{\clearlist{urldate}}
\AtEveryBibitem{\clearfield{urldate}}


Moreover, I would need this field for online materials, so I need a different solution. I had similar problems with other fields, which I just had to eliminate from the .bib database. For example, articles from PNAS have PMID number, which was printed in the bibliography even with

 eprint=false


in the preamble.

What I am doing wrong? I know experts here could write a complicated code to solve this particular problem, but maybe somebody knows how to do it using the options provided in biblatex or biblatex-chicago?

• You shouldn't put urldate in @article anyway. The articles are already published, so it makes no difference when you accessed them. The DOIs are furthermore permalinks, which definitely make urldate excessive. – Sverre Nov 30 '13 at 20:09
• @Sverre you are absolutely right, I do not need urldate here. But I am not deliberately putting them - they are inserted by biblatex and I cannot remove them! – homo_loquens Nov 30 '13 at 20:59
• biblatex doesn't insert anything into your .bib file. Whatever is in that file is something you (or someone else) actively put there. What I'm saying is that you shouldn't add the field urldate in your @article entries. – Sverre Dec 1 '13 at 12:35
• @Sverre why not? I could need it for reference and I am not including it manually anyway, it is included by Zotero. What I want biblatex to do is to include it only for appropriate types of entries such as online – homo_loquens Dec 1 '13 at 15:38
• @Sverre We are many who use Zotero or other backends as databases with other purposes than just creating bibliographies. The selection/customization of needed fields when rendering the bibliography is a must. – sunew Jan 14 '15 at 13:59

Instead of \AtEveryBibitem{\clearfield{urldate}} you might want to try

\AtEveryBibitem{%
\ifentrytype{online}
{}
{\clearfield{urlyear}\clearfield{urlmonth}\clearfield{urlday}}}


This makes sure the urldate is deleted (well, actually its parts urlyear, urlmonth and urlday are) only for non-@online entries.

Generally, one needs to be somewhat careful with .bib files exported by external programmes as these sometimes do not adhere to best practice.

Your sources look quite good though, save for issn = {0027-8424, 1091-6490}, in enikolopov_field_2013, isbn = {9781107306882 1107306884 9781107314634 1107314631 9781139343824 1139343823}, in simpser_why_2013 and several language = {en},. ISSN and ISBN fields should not contain several ISSN/ISBNs at once as these fields are printed verbosely and you certainly do not want to see all 6 different ISBNs in the bibliography, use the ISBN that the copy of the book you worked with had on its back. While in the language field the "[l]anguages may be specified literally or as localization keys" (the biblatex documentation, §2.2.2 Data Fields, p. 19), the localisation key version is preferable for localisation purposes, so english is better than en.

Consider this boiled-down version of the above MWE

\documentclass[11pt]{article}
\usepackage[authordate,backend=biber,bookpages=false,doi=false,isbn=false,url=false]                        {biblatex-chicago}
\usepackage{hyperref}
\usepackage{filecontents}

\begin{filecontents*}{\jobname.bib}
@article{enikolopov_field_2013,
title = {Field experiment estimate of electoral fraud in Russian parliamentary elections},
volume = {110},
issn = {0027-8424, 1091-6490},
url = {http://www.pnas.org/content/110/2/448},
doi = {10.1073/pnas.1206770110},
language = {english},
issue = {2},
pages = {448-452},
journaltitle = {Proceedings of the National Academy of Sciences},
author = {Enikolopov, Ruben and Korovkin, Vasily and Petrova, Maria and Sonin, Konstantin and Zakharov, Alexei},
urldate = {2013-10-28},
date = {2013},
}
\end{filecontents*}

\AtEveryBibitem{\clearlist{language}}
\AtEveryBibitem{%
\ifentrytype{online}
{}
{\clearfield{urlyear}\clearfield{urlmonth}\clearfield{urlday}}}

\begin{document}
\nocite{*}
\printbibliography
\end{document}


• @Sergey biblatex-chicago is a full style implementation, written with the anticipation that the user need not customize it. I wouldn't hesitate to contact the author, though. You could encourage him to post his source at GitHub. That way others could pitch in. The CMS styles are great, but a lot to take on for one person. – Audrey Dec 1 '13 at 0:46
• @Sergey Of course it is biblatex's job to decide what fields to print (actually, it's yours, biblatex just does what you tell it to do), my comment about external programmes was about non-standard or non-best-practice use of fields. Now considering the issue of to too much information, it seems to me not a bad idea at all that the standard styles allow output of a host of information (even information some people would not need or like to see) as it is very easy to suppress the output of certain fields (via \clearfield and friends) ... – moewe Dec 1 '13 at 7:29
• ... but it is surprisingly hard to add output of particular fields to an existing style (depending on the exact nature of that task the only solution might be to copy the whole bibliography driver and add the print statement). I would not call the solution above ad hoc, but rather short cut solution. One could always redefine \printurldate to only work in @online types (but why, this would certainly need more code?), one could just copy all the biblatex-chicago drivers and delete the line about \orinturldate, one could modify the doi+url+date macro. ... – moewe Dec 1 '13 at 7:34
• ... All these solutions, however, take much more code and are less simple than just the four lines above, which are, I think, very clear in showing what they are doing. Now, when it comes to biblatex-chicago, an implementation if the CMS guide to citations and bibliographies, you might want to contact the author if you find his style not adhering to said style guide (does the CMS prohibit access dates and URLs for @articles?). – moewe Dec 1 '13 at 7:40
• @moewe This and biblatex-chicago solutions I've posted are ad hoc in the sense that they aren't the (best) approach you'd take with any of the standard styles. Here for example url=false should have done the job. – Audrey Dec 1 '13 at 17:59