Internationally, there is growing empirical evidence showing that social capital contributes significantly to sustainability. Stimulating growth and development, implies an expansion of the stock of capital - this includes natural, physical or produced, financial, human as well as social capital. One general feature is that the poor have a lower opportunity cost of time and a lower stock of financial and physical capital, than the rich. Since social interaction is time-intensive, and social capital can often substitute for private capital, the poor may have to rely more upon social capital, than those who are better off, to secure sustainable livelihoods.

Social capital forms one of the core underpinnings of poverty and prosperity. Most economic behavior is embedded in networks of social relations. Social capital and trust can make economic transactions more efficient by giving parties access to more information, enabling them to co-ordinate activities for mutual benefit, and reducing opportunistic behavior through repeated transactions. Therefore social capital can play a significant part in shaping the economic outcomes at both micro and macro levels.

In terms of the family, social capital is often used among the poor to "insulate" themselves against shock, such as bad health and death, natural disasters or government cutbacks by pooling resources, such as food, credit or child-care. In addition to enabling poor people to start up small enterprises and increase their income, informal relationships often mean the difference between day-to-day survival and despair. On the community level, social capital has an impact on poverty by making government services more effective, facilitating the spread of information, enabling people to pool their resource and manage assets co-operatively, and giving people access to credit.

In terms of businesses, firm dense and overlapping social networks increase the likelihood of local economic development and co-operation by building trust and fostering shared norms. The social capital generated within and between businesses is especially important for lowering risk and uncertainty at the local level. Social capital facilitates valuable information exchange about products and markets and reduces the costs of contracts and extensive regulations and enforcement. Repeated transactions and business reputation provide the necessary incentives for business and other actors to act in mutually beneficial ways.

Societal level social capital is critical in determining how the government functions and what types of private sector develops in an economy. The states participation in economic development hinges on a delicate balance between external social ties (external social capital) and internal cohesiveness (internal social capital). Ideally, highly skilled and well-respected state bureaucracy uses its close working relationships with business leaders to enhance the market performance of private and public sector organizations. Government effectiveness, accountability and the ability to enforce rules fairy directly impact economic growth be enabling or hampering the development of domestic businesses and markets and encouraging or discouraging foreign investment.

Although measurement issues and challenges remain, a broad based consensus has developed on the importance of government social capital for economic performance. A similar consensus is rapidly developing on civic level social capital.

Social Capital for Industrial Development: Operationalising the concept :
http://siteresources.worldbank.org/INTSOCIALCAPITAL/Resources/social_capital_industrialization.pdf

Social Capital and Economic Development:
http://www.amazon.com/gp/reader/0415271339/ref=sib_dp_pt/103-9644334-1013418

Bridging and Bonding Social Capital Which type is good for economic growth?
http://www.eea-esem.com/papers/eea-esem/2003/119/EEA2003.PDF

Economic Growth and Social Capital in Asia
http://www.nber.org/papers/w5470

Social Capital and Economic Growth revisited
http://en.vatt.fi/file/vatt_publication_pdf/k307.pdf

Social Capital in Poverty Reduction and Economic Development
http://www1.worldbank.org/prem/poverty/scapital/topic/pov1.htm

Human and Social Capital are Keys to Well-Being and Economic Growth
http://www.oecd.org/document/25/0,3343,en_2649_34543_1918105_1_1_1_1,00.html