Congressional memberships as political advertising: evidence from the U.S. Senate.

• Author: Mixon, Franklin G., Jr.

1. Introduction

   Recent political battles over the federal legislative budget for 2002 have highlighted the political power wielded by so-called moderate legislators in the U.S. Senate. The epigraph above actually denotes the title of a webpage editorial from The Wall Street Journal that details the leverage displayed by so-called moderate senators, such as Jeffords (I-VT) and Chafee (R-RI), in shaping federal spending programs over the next 10 years. Elected officials often benefit from the acquisition of moderate labels or from sending centrist signals to voters and other constituencies such as political action committees (PACs). Recent research indicates that such behavior is quite possibly a financial-support maximizing strategy (Dempster and Westley 2000). In seminal studies, economists have examined the economics of information and its links to advertising, search, and signaling (Stigler 1961; Nelson 1970, 1974; Spence 1973). The generalized role of advertising in market functioning is now well known. Advertising signals are "technological devices" that reduce the full cost of exchange (Ekelund, Mixon, and Ressler 1995). The present article analyzes signaling, by elected officials, of moderate or centrist legislative behavior from a benefits/costs perspective. To do so, we provide statistical evidence regarding the tendency of senators to join the U.S. Senate Centrist Coalition, a congressional membership organization of moderate legislators.

2. The Benefits and Costs of Sending Centrist Signals: Framing the Hypotheses

   This article argues that there are some important benefits at the electoral level from sending centrist signals to voters (and other constituencies) through an alliance/coalition at the center of the elected/legislative body (i.e., the U.S. Senate). These benefits are in addition to the case where a senator joins the Centrist Coalition because he/she is a moderate in the home state or in his/her own party, although he/she may be conservative/liberal among the legislative body as a whole. For instance, the closeness of the 2000 presidential election displayed the importance of being in the political center. For Senate Democrats, working with the previous president (Clinton) required more liberal voting; these same Democrats may want to signal to the new Republican president (Bush) a willingness to cooperate. Additionally, those senators considering a future bid for the presidency, where the median voter is closer to the median of the Senate and not, perhaps, the median of their own state's electorate, may want to send centrist signals by joining a centrist alliance or coalition. It is also possible that new senators are signaling centrist behavior to other senators by allying with a centrist membership group. Older senators who have established reputations have little, if anything, to gain from joining a centrist coalition because their Senate colleagues (who are not rationally ignorant) and constituents are more familiar with their legislative record than is the case with new senators. (1) New senators, on the other hand, might gain from establishing ties with the median senator--one of the Senate's most decisive members--through signaling (see also Krehbiel 1998). (2)

   A number of studies have also argued that "moderateness" among legislators has an important fundraising-related electoral attribute. (3) Dougan and Munger (1989) argue that PACs will target more moderate legislators who have not established reputational (ideological) capital, suggesting that they favor specific legislative stances or political platforms. This notion is not inconsistent with research by Stratmann (1992), who argues that, if PAC money is successful at winning influence in any case, it is likely to have an impact at influencing the votes of more moderate legislators. His results confirm this belief. Using data drawn from campaign contributions in the agricultural sector of the economy, he finds that agricultural PACs do indeed divert more funds to the coffers of more moderate legislators. Last, Dempster and Westley (2000) provide econometric evidence indicating that moderateness is positively related to the ability of federal legislators to attract PAC money (from all sources) at the margin. They employ a unique measure of moderateness--the absolute difference between a legislator's ADA (Americans for Democratic Action) rating and his/her ACU (American Conservative Union) rating--and find negative (and robust) coefficients when regressed on the change in a legislator's PAC contributions across election cycles. These findings complement other work being done on signaling in the political process (see Kessler and Krehhiel 1996). (4)

3. Methodology

   This study examines the unobserved tendency of U.S. senators to join centrist voting coalitions or groups by observing whether or not members of the 107th U.S. Senate join or retain membership in the U.S. Senate Centrist Coalition at the start of the 107th Congress. (5) Therefore, we create a dichotomous variable--CENTER--equal to one if senator i (of the 107th Congress) joins or retains membership in the Centrist Coalition and zero otherwise. For the 107th Congress, 43 senators--23 Democrats and 20 Republicans--held membership in the Centrist Coalition. With the variable CENTER, we specify the following:

   (1) prob(CENTER = 1) = [([e.sup.1])/(1 + [e.sup.1])],

   where,

   (2) I = [alpha] + [beta]DEV.

   Equations 1 and 2 represent the familiar logit probability estimates. Equation 2 is a parsimonious model that is used to identify the political center of the U.S. Senate. (6) In Equation 2, DEV is the absolute value of the difference between senator i's voting ideology and the voting ideology of the median senator, m, from votes taken in the 106th Congress. We use W-NOMINATE voting tallies from members of the 106th Senate to score values for DEV. These tallies are based on roll-call votes taken by senators during the 106th Congress and am commonly used in the literature to measure political ideology (see Poole and Rosenthal 1997). Because CENTER takes a value of one for choices to join/retain membership in the Senate Centrist Coalition at the beginning of the 107th Congress and DEV represents W-NOMINATE tallies from the 106th Congress, data are drawn from 107th senators who also served in the 106th U.S. Senate. Therefore, our data set contains 89 observations.

   In Equation 2, DEV is expected to exhibit a negative relationship to the probability that CENTER is equal to one. In other words, if being centrist means displaying a centrist or moderate voting record, then the further a senator's voting record is from the median senator's (m) voting record, the less likely that senator will join/retain membership in the U.S. Senate Centrist Coalition. (7) A logit regression of Equation 2 points out that DEV is indeed negatively related to CENTER and significant at the 0.05 level (t-value = -2.47). (8)

   We explored the possibility that there are differences in perceptions of the Senate's "center" across the two parties. We ran a simple regression that includes DEV, DEM (a dummy variable equal to 1 for Democrats, and 0 otherwise), and DEV X DEM (an interaction term). This regression is capable of indicating whether one party or the other has a statistically greater likelihood of joining the Centrist Coalition and whether the parties have a different conception of the political center. The results of this logit specification are (t-values in parentheses):

   (3) CENTER = 4.3238 - 11.9048DEV + 13.2700DEM - 6.0245(DEV x DEM) (3.07) (-3.39) (2.08) (-0.84) pseudo [R.sup.2] = 0.326 model [chi square] = 39.34 nobs = 89 The results suggest that deviations from the Senate median significantly reduce the likelihood of Centrist Coalition membership and that Democrats are significantly more likely to join the Coalition than are Republicans. Equation 3 supports the notion that Democrats share a different conception of the political center in the U.S. Senate than Republicans. This regression explains the tendency of Senate Democrats to overjoin the Senate's Centrist Coalition (i.e., Democrats represented 49% of the Senate roster, but made up 53% of the Coalition's membership at the beginning of the 107th Congress).

4. Specification of the Costs and Benefits of Centrist Coalition Membership

   A more fully specified model of the probability of...