Social mobility refers to the movement of individuals or groups in social position over time. It may refer to classes, ethnic groups, or entire nations, and may measure health status, literacy, or education — but more commonly it refers to individuals or families, and their change in income. It also typically refers to vertical mobility—movement of individuals or groups up (or down) from one socio-economic level to another, often by changing jobs or marriage; but can also refer to horizontal mobility—movement from one position to another within the same social level. Social mobility can be the change in status between someone (or a group) and their parents/previous family generations ("inter-generational"); or over the change during one's lifetime ("intra-generational"). It can be "absolute"—i.e. total amount of movement of people between classes, usually over one generation (such as when education and economic development raises the socio-economic level of a population); or "relative" -- an estimation of the chance of upward (or downward) social mobility of a member of one social class in comparison with a member from another class. A higher level of intergenerational mobility is often considered praiseworthy, and the sign of greater fairness, or equality of opportunity, in a society.

Paul Davis Ryan (born January 29, 1970) is the U.S. Representative for Wisconsin's 1st congressional district, serving since 1999. He is a member of the Republican Party, and has been ranked among the party's most influential voices on economic policy.

Born and raised in Janesville, Wisconsin, Ryan graduated from Miami University in Ohio and later worked as a marketing consultant for Ryan Incorporated Central, run by a branch of his family. In the mid to late 1990s, he worked as an aide to United States Senator Bob Kasten, as legislative director for Senator Sam Brownback of Kansas, and as a speechwriter for former U.S. Representative and 1996 Republican vice presidential nominee Jack Kemp of New York. In 1998, Ryan won election to the United States House of Representatives, succeeding the two-term incumbent, fellow Republican Mark Neumann.

Ryan currently chairs the House Budget Committee, where he has played a prominent public role in drafting and promoting the Republican Party's long-term budget proposal. He introduced a plan, The Path to Prosperity, in April 2011 as an alternative to the budget proposal of President Barack Obama, and helped introduce The Path to Prosperity: A Blueprint for American Renewal in March 2012, in response to Obama's 2013 budget. Ryan is one of the three co-founders of the Young Guns Program, an electoral recruitment and campaign effort by House Republicans. He endorsed Republican presidential candidate and former Governor of Massachusetts Mitt Romney for the 2012 United States presidential election. Ryan has been considered as a possible running mate for Romney.

Philip Collins is the founder and curator of Barometer World in Merton, Devon.

He has been a non-aligned district Councillor for the Clinton Ward of Torridge District Council since 2001.

He is the secretary of the British Barometer Makers Association and a Fellow of the Royal Meteorological Society.

In sociology, social stratification is a concept involving the "classification of persons into groups based on shared socio-economic conditions ... a relational set of inequalities with economic, social, political and ideological dimensions." It is a system by which society ranks categories of people in a hierarchy Social stratification is based on four basic principles: (1) Social stratification is a trait of society, not simply a reflection of individual differences; (2) Social stratification carries over from generation to generation; (3) Social stratification is universal but variable; (4) Social stratification involves not just inequality but beliefs as well.

In modern Western societies, stratification is broadly organized into three main layers: upper class, middle class, and lower class. Each of these classes can be further subdivided into smaller classes (e.g. occupational).

These categories are particular to state-based societies as distinguished from feudal societies composed of nobility-to-peasant relations. Stratification may also be defined by kinship ties or castes. For Max Weber, social class pertaining broadly to material wealth is distinguished from status class which is based on such variables as honor, prestige and religious affiliation. Talcott Parsons argued that the forces of societal differentiation and the following pattern of institutionalized individualization would strongly diminish the role of class (as a major stratification factor) as social evolution went along. It is debatable whether the earliest hunter-gatherer groups may be defined as 'stratified', or if such differentials began with agriculture and broad acts of exchange between groups. One of the ongoing issues in determining social stratification arises from the point that status inequalities between individuals are common, so it becomes a quantitative issue to determine how much inequality qualifies as stratification.