Election Forecasting: A Sceptical View
Cees van der Eijk
This brief note contains some doubts about the predominant kind of statistical elec-
tion forecasting that is discussed in this issue. It is not meant to be a full-scale cri-
tique of the approach, the methods and the models that have been reported in the
literature. Rather, it is intended to be an attempt to explicate some of the recur-
ring feelings of disenchantment that can be experienced every time we come across
these forecasts.
It is, of course, worth emphasising that we should be positively inclined to any
attempt to specify statistical models of election outcomes, and to derive forecasts
from such models. Forecasting is a legitimate scientific enterprise that does not
deserve to be looked upon as a mere parlour game. In his excellent review of the
field, Michael Lewis-Beck (this issue) states that forecasting contributes to our
understanding of what causes election outcomes. But, this is exactly the cause of
so much disappointment. Forecasting is indeed a potentially powerful way to
develop and evaluate substantive theories, yet we usually learn so little (if any-
thing at all) from actual forecasting exercises. To elaborate this, this note briefly
discusses the theoretical core of statistical forecasting models, and argues that its
theoretical foundations are unsatisfactory. It then discusses the implausibility of the
functional specification of the core specifications of forecasting models. It then con-
cludes with some comments on the theoretical scope of the forecasting tradition.
It focuses particularly on Lewis-Beck’s overview of principles and practice, else-
where in this issue.
The Theoretical Core of Forecasting Models
Lewis-Beck pictures forecasting as a ‘theory-driven process’. More specifically, he
states ‘what counts is that the variables in the equation are based on strong elec-
toral theory’. He describes the Abramowitz model as built on ‘strong theory’
because it closely follows the core specification that Lewis-Beck earlier formulated
in his equation 2. This equation states that the vote share of the incumbent is a
linear function of the incumbent’s (lagged) popularity and of (lagged) economic
conditions. Is this a ‘strong theory’? It is doubtful, for a number of reasons.
First, theories of election results cannot escape the fact that an election outcome
is an aggregate of individual choices. The fact that the specific aggregation rule is
not an individual, but an institutional characteristic is irrelevant in this respect.
Election outcomes are aggregates of individual behaviours. In order not to reify
electoral outcomes, theories explaining them must therefore be ‘in sync’ with
theories of the individual choices that underlie the outcome (cf. Lazarsfeld and
Menzel 1969 [1961]). This does not require them to be identical. Indeed, to the
extent that factors explaining individual choice have no overall effect on the pre-
BJPIR: 2005 VOL 7, 210–214
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