Population growth technologySome economists found one key is that education and anti-discrimination policies well designed labor market and large and/or progressive tax and transfer system can all reduce income inequality . In many OECD developed western countries, income inequality has increased in past decades. In some countries, top earners have captured a large share of overall income gains, when for other income has risen only a little. Some see poverty as the relevant concern with the type of growth enhancing policy reforms advocated for each OECD developed countries and economic growth might have positive or negative side effects on income inequality.OECD (2011), it first highlights differences in some income inequality across the OECD and the factors driving them, such as cross-country differences in wage and non-wage income inequality as well as in hour worked and inactivity. OECD developed western countries can be divided into five groups to their pattern of inequality. For example, in five English-speaking countries ( Australia, Canada, Ireland, New Zealand, the United Kingdom) and the Netherlands wages are rather dispersed and the share of part-time employment is high, driving inequality in labor earnings above the OECD average means-tested public cash transfer and progressive tax.It seems income inequality will influence the developed countries, such as UK, Canada, Australia, New Zealand, US etc. economic growth. Although, technology change and globalization have played a role to influence the distribution of labor income. Some economists believe that any countries' policies will also influence income inequality. These policies factors include: technological education policies can increase different technology graduation rates from upper secondary and tertiary education and that also promote equal access to a well-designed different sector technology labor market policy can reduce inequality.A relatively high minimum wage narrows the distribution if labor income, but if set too high, it may reduce employment of inequality reducing effect. It tends to reduce labor earning inequality by ensuring a more equal distribution of earnings. Job protection reforms that make permanent and temporary contracts more even in their provisions low income wage dispersion of earnings is rather mixed, removing product market regulations can reduce labor income inequality by boosting employment, policies the faster the immigrants and fight all forms of discrimination reduce inequality, progressive tax policy play a key role in lowering overall income across the OECD developed countries.However, the redistributive fair income level between low level income labors and middle level income labors and high level income labors impact of developed countries, e.g. consumption taxes and real estate taxes tend to be regressive tax policy. Hence, it seems that reducing income inequality can cause the more fair income distribution between the high income level and the middle income level and the low income level labors. Then, it will let the developing countries or developed countries, such as US citizens feel that who can get real social welfare fairly, due to high technology development can boost economic growth in US society.Cheap medical development technology Some economists predict to make long term forecasts to reduce medical cost trends how will influence US economy. Also, they indicate short run cheap medical cost forecasts for first 1 to 5 years to reflect the particulars of specific groups, benefit packages, regional markets or cheap medical cost network providers and use their local cheap medical choice information and actuarial skills to improve accuracy and reasonability.