Descriptive Statistics of Survey Participants (N = 634).

<p>This table presents descriptive statistics of survey participants who rated audio clips of Supreme Court oral arguments made by male advocates. The data are self-reported by participants before beginning the audio survey.</p

OLS Baseline Results: Male Advocates.

<p>This table presents coefficient estimates from OLS regressions using data on Supreme Court oral arguments made by male advocates. The dependent variable is an indicator for whether the advocate won the case or not. Independent variables are voice-based ratings of advocate attributes made by survey participants, where untransformed ratings are integers ranging from 1 to 7 and normalized ratings are z-scored by participant. In columns 1-4, the unit of analysis is individual rating by oral argument, and in columns 5-8, the unit of analysis is oral argument average rating. Lawyer dummies are included where noted. Standard errors in parentheses are clustered by oral argument.</p

Correlations in Case Outcome and Trait Judgements of Male Lawyers (N = 33,666).

<p>This table presents correlations in participant normalized ratings and case outcomes. Each observation is an argument by participant rating. <i>Case Outcome</i> is = 1 if advocate won the case, and = 0 if advocate lost. Bonferroni-adjusted <i>p</i>-values in parentheses.</p

Descriptive Statistics of Survey Participants (N = 634).

<p>This table presents descriptive statistics of survey participants who rated audio clips of Supreme Court oral arguments made by male advocates. The data are self-reported by participants before beginning the audio survey.</p

Advocate Masculinity and Court Outcomes.

<p>Binned scatterplots illustrating the association between voice-based masculinity ratings and court outcomes. Binned scatterplots are a non-parametric method of plotting the conditional expectation function (which describes the average y-value for each x-value). Ratings are sorted into twenty quantiles with each point in the figure indicating the share of oral arguments won for a given ratings bin. The figure reflects the correlation between normalized ratings of masculinity and case outcomes of male advocates.</p

OLS Results: Male Petitioners versus Respondents.

<p>This table presents coefficient estimates from OLS regressions using data on Supreme Court oral arguments made by male advocates. Columns 1-5 (6-10) use data on oral arguments made by advocates for the petitioner (respondent). The dependent variable is an indicator for whether the advocate won the case or not. Independent variables are voice-based ratings of advocate attributes normalized by survey particiapnt. Lawyer and participant dummies are included where noted. Participant controls are age and dummies for each category given in the biographical questionnaire. Standard errors in parentheses are clustered by oral argument.</p

Petitioner Masculinity and Court Outcomes.

<p>Binned scatterplots illustrating the association between voice-based masculinity rating and court outcomes. Binned scatterplots are a non-parametric method of plotting the conditional expectation function (which describes the average y-value for each x-value). The figures are residual plots of the regressions presented in columns 2 (left) and 3 (right) of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164324#pone.0164324.t005" target="_blank">Table 5</a>, excluding the <i>masculine</i> independent variable. The lefthand (righthand) side figure plots residuals net of survey participant (lawyer) dummies. Ratings are sorted into twenty quantiles with each point in the figure indicating the mean residual for a given ratings bin.</p

Robustness Checks: Male Petitioners.

<p>This table presents coefficient estimates from regressions using data on Supreme Court oral arguments made by male advocates for the petitioner. The dependent variable is an indicator for whether the advocate won the case or not. Independent variables are voice-based ratings of advocate attributes normalized by survey particiapnt. Columns 1-2 report coefficient estimates using OLS with dummies for year of argument and number of cases argued by the lawyer where noted. Columns 3-4 report coefficient estimates using OLS where ratings that exceed the Mahalanobis distance of are omitted in column 3, and ratings by survey participants with scores in the top quintile on a measure of rating inconsistency are omitted in column 4 (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164324#pone.0164324.s005" target="_blank">S1 Table</a>). Columns 5-6 report baseline probit (logistic) regression results with marginal effects calculated at the means of the independent variables. Standard errors in parentheses are clustered by oral argument.</p

Summary Statistics of Case Outcome and Trait Judgements of Male Lawyers (N = 33,666).

<p>This table presents summary statistics of participant normalized ratings of our sample of 1634 oral arguments. Each observation is an argument by participant rating. <i>Case Outcome</i> is an indicator for whether the advocate won the case (= 1) in court or lost (= 0).</p

Survey filled by AMT participants.

<p>This figure is a screenshot of the survey matrix used by AMT participants to record their impressions of the audio recordings of advocates. The order and polarity of attributes were randomized across participants. Participants were not able to proceed to the next recording without completing the survey matrix and questions.</p