What is decision economics ? I would like to read about the basic
concepts of decision economics.

Decision or managerial economics is the application of economic
arguments to the problems of business management decision makimg.

For example, The Journal of Managerial and Decision Economics defines
its aim to l publish articles applying economic reasoning to
managerial decision making. Compared to other journals in economics,
the focus of this journal is more normative than positive and the
viewpoint is focused on managerial efficiency rather than on social
welfare. Articles are welcomed from economists and others using
economic reasoning in analyzing business problems. The journal will
publish articles from all of the functional areas of economics, as
long as these articles are useful for managerial decision making, and
from all the functional areas of business, so long as the articles use
economic reasoning.

Some examples: Articles in law and economics may use economic insights
to discuss ways in which firms can respond to legal problems.
Discussions of regulation or of public choice may highlight ways in
which firms can influence or adapt to government regulation. Articles
on public finance will emphasize reactions of firms to issues of
taxation. Consumer theory may be applied to marketing decisions.
Articles may stress ways in which firms can better adapt to labor
markets and may provide economic bases for personnel policies.
Analyses of industrial organization problems may suggest strategic
policies for firms. Economics may be used to analyze accounting
issues. Economics may be used to explain the existence and structure
of organizations.

The Learning and Teaching Support Network  web page has a useful 
short course and a very good set of references at

http://www.itu.int/ITU-D/pdf/2128-240-en.pdf

Hello partha

Decision making is usually regarded as the most important skill to be
learned in economics.
You might find it worthwhile to look at some of the books in the
reading list for the course in Political and Economic Decision Making
at Portland State University at the following link:

http://www.upa.pdx.edu/USP/syllabi/usp636.html

Hope this helps