However, their presidential powers of each differs considerably: Taiwan’s constitution grants extensive powers to the president, while in East Timor the president is largely a symbolic figure whose most important power is as supreme commander of the armed forces — a provision that was to have great importance during the internal conflict in East Timor in 2006. Mongolia sits somewhere between these two in terms of the scope of its presidential powers.

Despite their status as competitive electoral democracies, national politics in each of these countries has been hampered by recurrent problems of gridlocked government, political instability and politically-motivated violence during periods of ‘divided government’ when the president and the majority of the legislature come from different political parties. These pathologies are due, in part, to their semi-presidential constitutional structures, particularly the propensity of such systems to deliver periods of political cohabitation. These ‘split majorities’ have had a pronounced negative impact on political stability and effectiveness, weakening the consolidation of democracy in each of these three cases.

For significant periods of their recent democratic experience, the phenomenon of divided government placed immense pressures on the developing political systems of Mongolia, Taiwan and especially East Timor. One reason for this is that in each case, the initial period of divided government came early in the country’s democratic experience, and many of the political actors had no real sense of how to deal with it. Moreover, divided government brought with it a series of political problems that undermined political institutionalization, turning national politics into a competition between powerful individuals. This led to familiar patterns of political polarization, instability and violence emerging in each country, although a markedly different levels. While the severity of these differed considerably – the crisis in East Timor, for instance, was clearly of a different magnitude from that of Taiwan or Mongolia – the incidence of these problems of political polarisation, instability and violence can be compared to those times when unified governments were in place in each country.

Mongolia had the shortest period of divided government, with cohabitation lasting four years, from June 1996 to July 2000. East Timor’s period of divided government can be assessed as lasting from April 2002, when Xanana Gusmão won the country’s first presidential election with a massive 87 per cent of the popular vote, through to Mari Alkatiri’s resignation and replacement by Jose Ramos Horta as prime minister in July 2006. Taiwan’s experience of divided government was a constant throughout Chen Shui-bian’s presidency, from 2000 to 2008, as his Democratic Progressive Party controlled executive power but the opposition ‘pan-Blue’ coalition, led by the formerly-ruling Kuomintang, maintained a majority in the legislature.

One way of illustrating the problems of political stability in these semi-presidential countries is the World Bank’s Governance Matters database, which includes an aggregate measure of ‘political stability’ for all states drawn from a combination of public and private sources. This ‘political stability’ measure combines indices of politically-motivated internal and external violence in a given country with a separate measure of government durability, that is the government’s ability to carry out its declared programs, and to stay in office. As shown in Figure 1, which compares these indicators for each of the three country cases over the past decade, political stability tends to decline during periods of divided government.

Source: Kaufmann D., A. Kraay, and M. Mastruzzi 2007: Governance Matters VI: Governance Indicators for 1996-2006

In Mongolia, for example, the stability measures were at their lowest during the 1997–2000 period of cohabitation, but have risen since the resumption of single-party rule, at least until the aftermath of the 2008 parliamentary elections. In Taiwan, too, stability measures were at their highest in the late 1990s but declined with the election of President Chen Shui-bian in 2000 which ushered in Taiwan’s period of divided government, with the lowest levels reached in 2006. In East Timor, stability declined sharply between 2000 and 2002 as the UN administration prepared the country for independence, and have since declined considerably further, with the lowest levels reached in 2006 when the standoff between Prime Minister Alkatiri and President Gusmão came to a head.

These indicators help illustrate a key point: while semi-presidentialism has its benefits, it places unusual strains on new democracies. In particular, periods of divided government can put great stress on the stability of countries which have not yet developed established practices of political coexistence. In addition, the uncertainties of constitutional law in situations of shared power create their own problems: in these three country cases, disagreements over which particular office would exercise which particular constitutional powers was a recurring source of conflict. No constitution can codify all situations which office-holders are likely to face, meaning that even the most thorough constitutional text will inevitably leave some grey areas unspecified. This is a particular problem for semi-presidential constitutions, as it is precisely those grey areas of uncertainty which can provide the basis for ongoing conflict.