Wartime Elections


How does war (or any highly significant policy) affect the electorate’s vote choice? Moreover, how do different signals regarding the state of the war (success or failure) help the electorate to form their belief about the incumbent’s war policy? The political science literature regarding the affect of war on elections has a long history, beginning with John E. Mueller’s famous finding that as (the log of) casualties in war increases, favorable public opinion of the war decreases. Recently, Gelpi, Feaver, and Reifler have hypothesized that while the public is adverse to casualties, the tolerance for the human costs of war are shaped by two attitudes: (1) Whether the war justified and (2) Whether the war is likely to be a success – the later being more important than the former. See their book for the full argument.

We also know that the electorate often formulates their belief by using heuristics (cues) from elite sources. See Popkin’s The Reasoning Voter and Lupia and McCubbins’s The Democratic Dilemma (the latter uses a formal modeling and experimental approach)We also know from Zaller’s The Nature and Origins of Mass Opinions that public opinion is heavily influenced by elite discourse; however, for Zaller’s theory, elite cues are not necessarily differentiated (i.e. the effect of cues from the media, incumbent, and opposition party on the electorate is not investigated separately). My research is focused on separating multiple (and potentially competing) cues in the belief formation process.

Accurate vs. Biased Signals

I have developed a theory which looks at how different elite cues interact during the electorate’s belief formation about public policies which have especially high significance – with war being my primary focus. My signalling model blends objective but potentially inaccurate cues about the state of a policy (i.e. is the war on track for success or failure?) with biased cues from fully informed actors regarding the continuation of the policy (i.e. should the war be ended or not). The biased actor desires to get elected but also has preferences over the national interest . The noisy but objective signal comes from an actor I am calling the “Media”, while the biased signal comes form the “Opposition Party”.

Now I am sure that some people are already discounting my model because I am assuming that the “Media” is an unbiased actor. I don’t think this assumption is so crazy. I am mealy assuming that the electorate receives some objective (but possibly inaccurate) information from a news source. For example, casualties are reported, battle outcomes are reported, the taking of city is reported, etc. I would consider what some people call “New Media Sources” – which are often highly partisan and biased – to be a part of the actor I am calling the “Opposition Party”. These sources have a biased partisan opinion, but probably want what is best for the U.S.’s national interest as well. Thus, I think the assumptions of my model are reasonable. Even so, assumptions do not have to be perfectly accurate as long they are useful in telling us something interesting about the world. The empirical implications of my model will be judged by my experimental and large-N statistical tests (which I hope to post some info on soon).

The Model

The game begins with Nature (N) selecting the value of continuing the war, $latex \omega $. There are two states of the world, $latex \omega = \overline{\omega} $ and $latex \omega = \underline{\omega} $, where $latex \overline{\omega} $ is the value for a war that is worth continuing and $latex \underline{\omega} $ is the value for a war which isn’t worth fighting. In the game, $latex q$ is the probability that $latex \omega = \overline{\omega} > 0$, while $latex (1-q)$ is the probability that $latex \omega = \underline{\omega} < 0$.

Next, N sends a noisy signal, $latex s \in \{l,h\}$, to the Media (M), about $latex \omega$. With probability $latex \alpha \in (0.5,1)$, M receives an accurate signal and with probability $latex (1-\alpha)$, M is given an inaccurate signal. Therefore, $latex Pr(s = h | \omega = \overline{\omega}) = Pr (s = l | \omega = \underline{\omega}) = \alpha$; in other words, $latex \alpha$ signifies the probability that the state of the world matches the signal given by M. Also, $latex Pr(s = l | \omega = \overline{\omega}) = Pr(s = h | \omega = \underline{\omega}) = (1-\alpha)$; thus, $latex (1-\alpha)$ is the probability of  M being given an inaccurate signal which fails to match the state of the world. This means that, $latex Pr(s = h) = \alpha q + (1- \alpha)(1-q)$, while $latex Pr(s = l) = \alpha(1-q) + (1- \alpha)q$. This implies that $latex Pr(\omega = \overline{\omega} | s = h)$ and $latex Pr(\omega = \overline{\omega} | s = l)$ follows from Bayes’ rule:

$latex Pr(\omega = \overline{\omega} | s = h) = \frac{\alpha q}{\alpha q + (1 – \alpha) (1-q)} $


$latex Pr(\omega = \overline{\omega} | s = l) = \frac{(1 – \alpha)q}{(1 – \alpha) q + \alpha (1-q)} $

Upon observing $latex s$, the Opposition (O), announces their desire to either continue or end the war, $latex \rho \in \{c,e\}$. I assume that $latex \rho$ predicts what O would do if elected. O is electorally motivated but also values the national interest at a rate of $latex \iota \sim u[0,\overline{\iota}]$.

In the final move of the game, the Electorate (E) decides whether to retain the incumbent or elect O. When E retains the incumbent, O receives $latex \omega\iota$ while E receives $latex \omega+\xi$, where $latex \xi \in [-1,1]$ represents the value of the incumbent relative to O with respect to economic or other domestic issues. This term may represent retrospective evaluations, prospective evaluations, differences in policy platforms, or combination thereof. The value of $latex \xi$ is common knowledge.

If E elects O and O had set $latex \rho=c$, O receives $latex \beta \in (0,1)$, which reflects the benefit of holding office plus $latex \omega \iota $, while E receives $latex \omega$. If O sets $latex \rho=e$, deciding to end the war, O receives $latex \beta$ and E receives 0.

In the game, I assume that O knows $latex \omega$ while E does not. However, E knows that O knows the true value of $latex \omega$, and may update their prior belief $latex q$ to $latex q_{s}^{\rho}$, which reflects the information revealed by M and the signal given by O. Specifically,

$latex Pr(\omega=\overline{\omega} | s = h, \rho=c) = q_{h}^{c}$
$latex Pr(\omega = \overline{\omega} | s = h, \rho = e) = q_{h}^{e}$
$latex Pr(\omega = \overline{\omega} | s = l, \rho = c) = q_{l}^{c}$
$latex Pr(\omega = \overline{\omega} | s = l, \rho = e) = q_{l}^{e}$

There several general equilibria in the game; however I am only focusing on one (which I think is the most interesting) semi-separating equilibrium, which I call Opposing Victory.

Opposing Victory


There exists a semi-separating equilibrium where the Opposition party signals they want to end the war ($latex \rho = e$) with probability $latex \frac{\beta}{\overline{\iota} \ \overline{\omega}}$ if $latex \omega = \overline{\omega}$ and signals that they want to end the war ($latex \rho = e$) if the actual state of the war is not worth fighting ($latex \omega = \underline{\omega}$). Thus, the Opposition is semi-separating when the true state of the war is worth fighting. Moreover, the Opposition Party’s behavior is irrespective of the signal the Media sends (i.e. $latex s = h$ or $latex s = l$). The Electorate retains the Incumbent iff their belief that the true state of the war is going well ($latex q_{h}^{e} \geq \hat{q^{e}}$) when the Media says it is going well ($latex s = h$) and the Opposition Party wants to end the war ($latex \rho = e$); iff the their belief that the true state of the war is going well ($latex q_{l}^{e} \geq \hat{q^{e}}$) when the Media says it is going poorly ($latex s = l$) and the Opposition Party wants to end the war ($latex \rho = e$); and with certainty if the Opposition Party wants the was to continue ($latex \rho = c$), irrespective of the Media’s signal ($latex s$).

Because O values the national interest at a rate of $latex \iota \sim U[0, \overline{\iota}]$, we can find the probability that $latex \iota$ is above or below $latex \frac{\frac{\beta}{\omega}}{\overline{\iota}}$, which is the same as $latex \frac{\beta}{\overline{\iota} \ \overline{\omega}}$.

Assuming that O and E abide by the strategies outlined above, then Bayes’ rule tells us that,

$latex Pr(\omega = \overline{\omega} | s = h,\ \rho = c) =$

$latex q_{h}^{c} = \frac{q (1 – \frac{\beta}{\overline{\iota} \ \overline{\omega}})(\alpha)}{q (1 – \frac{\beta}{\overline{\iota} \ \overline{\omega}})(\alpha) + 0 (1-q)(1 – \alpha)} \Rightarrow q_{h}^{c} = 1$


$latex Pr(\omega = \overline{\omega} | s = l,\ \rho = c) =$

$latex q_{l}^{c} = \frac{q (1 – \frac{\beta}{\overline{\iota} \ \overline{\omega}})(1 – \alpha)}{q (1 – \frac{\beta}{\overline{\iota} \ \overline{\omega}})(1 – \alpha) + 0 (1-q)(\alpha)} \Rightarrow q_{l}^{c} = 1$


$latex Pr(\omega = \overline{\omega} | s = h,\ \rho = e) =$

$latex q_{h}^{e} = \frac{q \frac{\beta}{\overline{\iota} \ \overline{\omega}}(\alpha)}{q \frac{\beta}{\overline{\iota} \ \overline{\omega}}(\alpha) + 1 (1-q)(1 – \alpha)}$


$latex Pr(\omega = \overline{\omega} | s = l,\ \rho = e) =$

$latex q_{l}^{e} = \frac{q \frac{\beta}{\overline{\iota} \ \overline{\omega}}(1 – \alpha)}{q \frac{\beta}{\overline{\iota} \overline{\omega}}(1 – \alpha) + 1 (1-q) (\alpha)}$

Now that we have E’s beliefs we can see if the Opposing Victory equilibrium holds. If $latex \xi > 0$ and O advocates for continuing the war, then E always retains the incumbent. If $latex q_{h}^{e} < \hat{q^{e}}$ and $latex q_{l}^{e} < \hat{q^{e}}$, O is willing to play the strategies constructed by the Opposing Victory equilibrium. Provided these inequalities hold, the semi-separating equilibrium is established. O always advocates for ending the war when the war is not worth fighting but can also advocate ending the war when it is worth fighting with probability $latex \frac{\beta}{\overline{\iota} \ \overline{\omega}}$; thus, O’s strategy depends on $latex \iota$ when $latex \omega=\overline{\omega}$ but not when $latex \omega=\underline{\omega}$.

What Does This Tell Us?

This equilibrium suggests that it is possible for the Media to mistakenly report that the war is not worth continuing, the Opposition then advocates ending the war, and the Electorate replaces the incumbent with the Opposition effectively ending the war, even though, in truth, the war was worth continuing.

This equilibrium also suggests that the Media can correctly report that the war is worth continuing, but the Opposition still advocates ending the war  and the Electorate replaces the incumbent with the Opposition, effectively ending the war that, again, would have been worth continuing and M revealed was worth continuing.

Thus, we can get a rather tragic outcome when the Electorate’s belief is conditioned on both signals. Much of this is driven by the Opposition’s value of the national interests vs. the benefits of getting elected. Interestingly, in the initial stages of a war we often see a “rally” effect where the Opposition party backs the Incumbent and we perceive a unified foreign response. However, we also observe that as the war continues, the Opposition party can begin to pull away from the Incumbent’s foreign policy and criticize the Incumbent’s policy. More often than not, the party of the Incumbent is inconsequential to the criticism. In other words, what matters more is not whether the Incumbent is a Democrat or a Republican, but simply that one party is in office while one is out. As already stated most explanations revolve around casualties or citizen beliefs about the success of the war. My explanation demonstrates that, under conditions of competing information, biased signals can be dominant, leading the electorate terminate an other wise successful war. More importantly, what leads to the competing signals and to the tragic outcome is the democratic process – or at least the desire of the Opposition Party to get elected.

Policy Extension

This suggests a rather tragic outcome where biased signals are dominant, whereby the democratic political process and the Opposition Party’s desire to get elected, has them advocate ending a public policy (in this case war) which is actually successful. I believe that this model can be extended to any public policy which carries significant weight with the electorate. For example, in the 2012 presidential election Obama’s healthcare policy is likely to be one of those issues where the opposition party will attack its ability to be successful. The Media in this case will likely report on the achievements (or non-achievements) of the legislation. My model suggests that any policy (which carries significant weight with the electorate) can be terminated based the electorate’s beliefs, even though the policy is objectively successful. Of course I am not saying Obama’s healthcare legislation is successful or not. What I am saying is the democratic process can lead perfectly successful legislation to be terminated because the Opposition Party has an incentive to get in office.

Suggestion are welcome.