expected to have their own bedroom, rather than sharing with siblings as was the case until recently. Rural areas also tend to be more conservative, with less contraception and abortion than urban areas. Reduction of child labour Countries which have a high fertility rate are usually less developed countries, where families rely on children to help them, with labour such as agricultural work, tending to livestock, or even paid work. In such countries child labour is quite common, with children bringing money at home, or actively supporting the family through physical work. By contrast, in high-income nations, child labour is banned, and it is parents who invest very high costs into their children. Views on the "ideal" family Although fertility rates are often discussed in terms of state policies (e.g. financial benefits, combining work with family etc.), the deeply entrenched social views on what constitutes an "ideal" family may play a crucial role: if parents do not envision large families in a positive way, it is difficult to "convince" them to have many children. In this regard, there are major differences between European countries: while 50.23% of women aged 15–39 state that the "ideal" family has 3 or more children in Estonia, and 46.43% say this in Finland; only 11.3% say this in Czech Republic, and 11.39% in Bulgaria. Contraception Changes in contraception are also an important cause, and one that has seen dramatic changes in the last few generations. Legalization and widespread acceptance of contraception in the developed world is a large factor in decreased fertility levels; however, for instance in a European context where its prevalence has always been very high in the modern era, the fertility rates do not seem to be influenced significantly by availability of contraception. While contraception can reduce the number of unwanted births and contribute to a smaller ideal family size, contraception does not start fertility reductions nor substantially effect their size, with these being attributable to other factors. Assisted reproductive technology The availability of assisted reproductive technology (ART) may foster delay of childbearing, because many couples think that it can solve any future fertility problems. Its effect on total fertility rate is extremely small but government support for it is beneficial for families. Human Development Index The Human Development Index (HDI) is a composite statistic of life expectancy, education, and per capita income indicators, which are used to rank countries into four