precisely of its perception), range from Gallup’s opinion surveys—where a sample
of the polity is asked how common corruption is and at what scale it operates—to
surveys of company executives that estimate the share of their companies’ revenues
that are spent in bribes.19 On the one hand, the high correlation of the aggregated
indexes, originated from different sources, gives some confidence in the belief that
they are correct proxies for corruption. On the other hand, it should be noted that
the definition of corruption can be interpreted differently in different cultural contexts
and that there can be “emotionally driven” answers to survey. Thus, when a
corruption scandal is escalating, the interviewees will possibly overrate the level
of corruption, just as when the economy is booming interviewees can have a more
positive attitude about the government and the civil servants. While some of these
concerns are taken care of by the way the polls are realized and aggregated, a margin
of uncertainty is inevitable (see Kaufmann et al. 2005). Critiques of these indexes
have, among other things, focused on the fact that they measure perceptions
rather than “real” corruption levels. However, as it has been shown extensively in
the empirical literature, even though these indexes may delineate the perception of
corruption rather than its existence, it appears that perceptions have an impact on
the economy and that the indexes have a high explanatory power when used as independent
variables in econometric analyses (for a review see Jain 2001). Moreover,
some of the sources, such as surveys of company executives’ expenditure on bribes
as a percentage of revenues, are more akin to estimates of corruption rather than
simple polling of opinions.20, 21