for income convergence have receded according to the EBRD's prognosis, unless there are additional productivity-enhancing structural reforms. The recent history of transition suggested that weak political institutions and entrenched interest groups had hindered economic reform. The EBRD's Transition Report 2013 looked at the relationship between transition and democratization. The report acknowledged that the academic literature was divided on whether economic development fostered democracy but argued that there was nonetheless strong empirical support for the hypothesis. It suggested that countries with high inequality were less inclined to support a limited and accountable state. In general, the proportion of the population with an income of between US$10–50 a day (the so-called "middle class") correlated with the level of democracy; however this correlation disappeared in transition countries with high income inequality. Those countries with large natural resource endowments, for example oil and gas producers like Russia and Kazakhstan, had less accountable governments and faced less electoral pressure to tackle powerful vested interests because the government could rely on resource rents and did not have to tax the population heavily. Countries with a strong institutional environment – that is, effective rule of law, secure property rights and uncorrupted public administration and corporate governance – were better placed to attract investment and undertake restructuring and regulatory change. To spur further economic reform and break out of a vicious circle, the EBRD Transition Report 2013 proposed that the transition economies should: Open up trade and finance, which made reform more resilient to popular pressure ("market aversion") and meant that countries could access the EU single market either as member states or through association agreements (such as those being negotiated with Ukraine, Moldova and Georgia); Encourage transparent and accountable government, with media and civil society scrutiny, and political competition at elections; Invest in human capital, especially by improving the quality of tertiary education. Countries in transition Although the term "transition economies" usually covers the countries of Central and Eastern Europe and the former Soviet Union, this term may have a wider context. Outside of Europe, there are countries emerging from a socialist-type command economy towards a market-based economy (e.g., China). Despite such movements, some countries have chosen to remain non-free states with regard to political freedoms and human rights. In a wider sense, the definition of transition economy refers to all countries which attempt to change their basic constitutional elements towards market-style fundamentals. Their origin could be