Editing Gini coefficient (section)

===Benefits and income in kind===
Inaccuracies in assign monetary value to [[income in kind]] reduce the accuracy of Gini as a measurement of true inequality.

While taxes and cash transfers are relatively straightforward to account for, other government benefits can be difficult to value. Benefits such as subsidized housing, medical care, and education are difficult to value objectively, as it depends on the quality and extent of the benefit. In absence of a free market, valuing these income transfers as household income is subjective. The theoretical model of the Gini coefficient is limited to accepting correct or incorrect subjective assumptions.

In subsistence-driven and [[informal economies]], people may have significant income in other forms than money, for example, through [[subsistence farming]] or [[barter]]ing. These forms of income tend to accrue to poor segments of populations in emerging and transitional economy countries such as those in sub-Saharan Africa, Latin America, Asia, and Eastern Europe. Informal economy accounts for over half of global employment and as much as 90 percent of employment in some of the poorer sub-Saharan countries with high official Gini inequality coefficients. Schneider et al., in their 2010 study of 162 countries,<ref>{{cite journal|first1=Friedrich|last1=Schneider|first2=Andreas|last2=Buehn|first3=Claudio E.|last3=Montenegro|s2cid=56060172|year=2010|title= New Estimates for the Shadow Economies all over the World|journal=International Economic Journal|volume=24|issue=4|pages=443–461|doi=10.1080/10168737.2010.525974|hdl=10986/4929}}</ref> report about 31.2%, or about $20 trillion, of world's [[Gross domestic product|GDP]] is informal. In developing countries, the informal economy predominates for all income brackets except the richer, urban upper-income bracket populations. Even in developed economies, 8% (United States) to 27% (Italy) of each nation's GDP is informal. The resulting informal income predominates as a livelihood activity for those in the lowest income brackets.<ref>{{cite book|title=The Informal Economy|publisher=International Institute for Environment and Development, United Kingdom|year=2011|url=http://pubs.iied.org/pdfs/15515IIED.pdf |archive-url=https://web.archive.org/web/20120803160544/http://pubs.iied.org/pdfs/15515IIED.pdf |archive-date=2012-08-03 |url-status=live|isbn=978-1-84369-822-7}}</ref> The value and distribution of the incomes from informal or underground economy is difficult to quantify, making true income Gini coefficients estimates difficult.<ref name=mfeld>{{cite web|title=Is income inequality really the problem? (Overview)|first=Martin|last=Feldstein|date=August 1998|publisher=US Federal Reserve|url=http://www.kc.frb.org/publicat/sympos/1998/S98feldstein.pdf|access-date=2 August 2012|archive-date=3 August 2012|archive-url=https://web.archive.org/web/20120803160558/http://www.kc.frb.org/publicat/sympos/1998/S98feldstein.pdf|url-status=dead}}</ref><ref name=tandw>{{cite book|title=Principles of Microeconomics: Global Financial Crisis Edition|first1=John|last1=Taylor|first2=Akila|last2=Weerapana|year=2009|isbn=978-1-4390-7821-1|pages=416–418|publisher=Cengage Learning }}</ref> Different assumptions and quantifications of these incomes will yield different Gini coefficients.<ref>{{cite journal|title=Income Inequality and the Informal Economy in Transition Economies|first1=J. Barkley Jr. |last1=Rosser|first2=Marina V.|last2=Rosser |first3=Ehsan|last3=Ahmed |s2cid=49552052 |journal=Journal of Comparative Economics|date=March 2000|volume= 28|issue=1|pages=156–171|doi=10.1006/jcec.2000.1645}}</ref><ref>{{cite web|title=Earnings inequality and the informal economy: evidence from Serbia|first1=Gorana|last1=Krstić |first2=Peter|last2=Sanfey |publisher=European Bank for Reconstruction and Development|date=February 2010|url=http://www.ebrd.com/downloads/research/economics/workingpapers/wp0114.pdf |archive-url=https://web.archive.org/web/20120803160550/http://www.ebrd.com/downloads/research/economics/workingpapers/wp0114.pdf |archive-date=2012-08-03 |url-status=live}}</ref><ref>{{cite report|title=The Size of the Shadow Economies of 145 Countries all over the World: First Results over the Period 1999 to 2003|first=Friedrich|last=Schneider|date=December 2004|ssrn=636661|hdl=10419/20729}}</ref>