of 29 rich democracies, single parenthood is not significantly associated with childhood poverty. In the U.S., the association between single motherhood and poverty has been falling since the 1970s, and childhood poverty is now much more closely associated with parental employment than marriage status. The 1996 welfare reforms in the U.S. were shown to increase employment and reduce dependence on welfare by single parents, but did not have any measurable effect on single motherhood. International studies in developing countries find no effect between conditional vs unconditional cash aid on future employment. Structural theories Economic and demographic contexts have been shown to increase poverty directly, as well as change parent behavior in ways that increase poverty. For example, local economic growth and development, state of industrialization, and spatial or skills mismatches can all affect poverty directly by limiting the opportunity for employment. Demographics are also correlated with poverty, including neighborhood disadvantage, residential segregation, age/sex composition, or living in a rural area. Structural effects seem to vary across time and place and research often comes to contradictory conclusions. For example, urbanization in rich countries is often associated with displacing the poorest members of the community, which increases their average poverty levels. However, in developing countries, local economic growth is more often associated with reducing poverty of the most poor. Political theories Institutions and power can lead to policy that tends to increase or decrease childhood poverty irrespective of local culture or current behaviors. Power resource theory is one of the most popular political explanations for poverty. Since elites and businesses are typically favored in the distribution or political power in a capitalist democracy, less advantaged groups may gain political power by mobilizing together (for example for labor unions or voting). In the United States, working poverty is lower in states that have higher levels of unionization. Country-wide poverty tends to be lower when there is greater unionization, a higher proportion of women in parliament, and when the government of a stable democracy is controlled by Left-wing parties. The effects of leftist politics appear to have a much larger effect on poverty levels than structural factors or individual behavior. Another political theory focuses on institutions. Institutionalists claim that poverty is caused by how institutions (such as laws or regulations) affect the long-term distribution of resources. One piece of evidence is that poverty rates don't respond quickly to changes in power or elections, and