prevails, when, how, and why did it change. Focusing on the power of prime
minister and cabinet is limiting, whereas these questions open the possibility of
explaining similarities and diVerences in executive politics (Elgie 1997 , 231 and
citations). Whatever the preferred analytical approach, the key point is that the
comparative analysis of executives must not, as in the case of Westminster systems,
become inward looking and oblivious to developments elsewhere in comparative
politics.
7 Conclusions—Whither the Study of
Executives?
.........................................................................................................................................................................................
Any commentator who underestimates the longevity of and commitment to
modernist-empiricism does so at his or her peril. There is a lifetime’s work for
any number of political scientists in documenting and comparing trends in
parliamentary government in the Commonwealth and Western Europe. All the
topics covered earlier were and remain challenges.
For those modernist-empiricists with even greater aspirations, rational choice
institutionalism oVers a thoroughgoing redeWnition of theWeld. Tsebelis’s ( 2002 )
analysis of veto-players is the key contribution. His general theory of institutions
posits that governments, in order to change policies, must get individual actors
or veto-players to agree. Institutional veto-players are speciWed by the constitu-
tion and partisan veto-players are speciWed by the party system. Each country has
a set of veto-players, with speciWc ideological distance between them, and a
degree of cohesion. This conWguration is the status quo. When there are many
veto-players, signiWcant change in the status quo is impossible, giving policy
stability. Variations in the institutional framework cease to be signiWcant. Rather,
countries diVer in ‘‘the number, ideological distances, and cohesions of the
corresponding veto-players.’’ So, he reverses the usual meaning of presidential
and parliamentary government: ‘‘agenda control most frequently belongs to
governments in parliamentary systems and parliaments in presidential ones’’
(Tsebelis 2002 , 67 ).
Such propositions are nothing if not challenging, so debate ensues. For example,
Strøm, Mu ̈ller, and Bergman ( 2003 , chs. 3 and 23 ) argue veto-players diVer by type
and speciWc authority. They distinguish between a dictator whose consent is both
necessary and suYcient, a veto-player whose consent is necessary, a decisive player
whose consent is suYcient, and a powerful player who can credibly threaten to take
338 r. a. w. rhodes