The only ready-made bibliography style file I know of that typesets the contents of each entry's abstract field in the References (but not as part of a citation call-out) is called abstract.bst.
As the example below shows, the abstract bibliography style isn't programmed to output information (even if present) in the url and doi fields. If any TeX-special characters (such as $, %, #, and &) are present in the abstract field, they must be escaped with backslash characters per the usual TeX/LaTeX syntax rules. If the abstract field happens to contain any paragraph breaks (as is the case in the example shown below), one must insert suitably-placed \par directives if the paragraph breaks are to be preserved.
The key field of each entry is shown. (In the example below, the key field is given by the string feldstein:2011.) In fact, the entries are sorted alphabetically on the key fields, not alphabetically by authors' surnames.
\RequirePackage{filecontents}
\begin{filecontents}{mybib.bib}
@techreport{feldstein:2011,
title = "The {Tax Reform Act} of 1986: Comment on the 25th Anniversary",
author = "Martin S. Feldstein",
institution = "National Bureau of Economic Research",
type = "Working Paper",
series = "Working Paper Series",
number = "17531",
year = "2011",
month = "October",
doi = "10.3386/w17531",
URL = "http://www.nber.org/papers/w17531",
abstract = {The Tax Reform Act of 1986 was a powerful pro-growth force
for the American economy. Equally important, as we look back on it
after 25 years, we also see that it taught us two important
lessons. First, it showed that politicians with very different
political philosophies on the right and on the left could agree on
a major program of tax rate reduction and tax reform. Second, it
showed that the amount of taxable income is very sensitive to
marginal tax rates.
\par
More specifically, the evidence based on the 1986 tax rate
reductions shows that the response of taxpayers to reductions in
marginal tax rates offsets a substantial portion of the revenue
that would otherwise be lost. This implies that combining a
broadening of the tax base that raises revenue equal to 10 percent
of existing personal income tax revenue with a 10 percent across
the board cut in all marginal tax rates would raise revenue equal
to about four percent of existing tax revenue. With personal
income tax revenue in 2011 of about \$1 trillion, that four percent
increase in net revenue would be \$40 billion at the current level
of taxable income or more than \$500 billion over the next ten
years.},
}
\end{filecontents}
\documentclass{article}
\bibliographystyle{abstract}
\usepackage{url} % doesn't get used since "abstract" bib style doesn't show contents of 'url' fields
\usepackage[english]{babel}
\begin{document}
\nocite{*}
\bibliography{mybib}
\end{document}
