What Color Is The Taxpayer’s Money?
Introduction
We elect members of the United States Congress every 2 years from our states and they go to Washington D.C. to represent us. Each member of Congress is given a budget, using taxpayer money, to run their operations. They have to hire staff and travel back and forth between their district and the nation’s capital. Each member decides how they use the budget in order to do their job. Does the gender of the member of Congress or their political party affiliation make a difference in how much they spend? Do the disbursements made to members of Congress from Colorado show the same general patterns as national data? Are the differences statistically significant? This post explores all of these questions, in order to provide readers with a good summary and highlight any interesting patterns that are worth pointing out.
Data
From the year 2009 onwards, the U.S. House of Representatives has published disbursement data and ProPublica has standardized them into CSV files. I used the disbursement data from the third quarter of 2021, when the 117th Congress was in session, along with Congress member data (documentation). This member data includes information about their gender and party affiliation, among other things. Aggregating the quarterly disbursement data for each Congress member and combining it with their personal information, we compare the payments and look for similarities or differences in the distribution of amounts paid, based on gender or party affiliation, and assess how data about the Congress members from Colorado compares to national data that includes Congress members from all states.
Distribution
The histogram below shows the distribution of the total disbursement amounts paid in 2021Q3, per U.S. Congress member. The red line shows the median. The histogram shows one peak, between $300,000 and $400,000, and a majority of Congress members spent around this amount in the quarter. In fact, almost all of the individual member spending amounts for the quarter were between $150,000 and $500,000. While that may seem like a huge amount of spending for one quarter for one member, if we consider that a U.S. Congress member may have to hire a few people and travel back and forth between their constituency and Washington, D.C., then the amount does not seem that high.
Spending differences by gender and party
The Pew Research Center says that the gender pay gap in the U.S. has not changed much in two decades. Does this gender inequality also exist in the U.S. Congress disbursement data? The chart below shows the distribution of the total amount spent by a single U.S. Congress member in 2021Q3, broken down by gender. The blue box plot shows the data for male Congress members and the pink box plot shows the data for female Congress members. The median for the two groups is almost identical, but the male data seems to have a bit more variability and outliers. The median for each gender group is around $325.00 per member. Using an independent t-test, there is no significant difference (t = -0.179, p = 0.858) in spending by gender. Based on this evidence, we can conclude that the disbursements to the U.S. Congress members do not suffer from a gender gap.
Republicans are generally considered to be more fiscally conservative compared to Democrats and it is interesting to examine whether the Congress disbursement data confirms or contradicts this general public opinion. The chart below shows the distribution of the total amount spent by a single U.S. Congress member in 2021Q3, broken down by party affiliation. The blue box plot shows the data for Democratic Congress members and the red box plot shows the data for Republican Congress members. The median for the two groups is different, with the typical Republican member’s disbursements being less compared to the typical Democratic member. Also, the Republican members’ data has more variability and outliers. Using an independent t-test, there is a significant difference (t = 2.0796, p = 0.038) in spending between the two political parties. Based on this evidence, we can conclude that the disbursement data confirms the general public opinion about the fiscal conservatism of Republicans.
Showing the data broken down by political party affiliation as well as gender clearly shows the interdependencies between these two variables. The chart below shows the distribution of the disbursement data for Republican Congress members on the left and Democratic members on the right. For each party, the blue box plot shows the data for males and the pink box plot shows the data for females. It can be seen clearly that, for any single party, the median does not really change across gender lines. The median for Democratic members is seen to be higher than Republicans, but, again, gender does not make a huge difference within one party.
Spending differences between Colorado and national averages
What does the data about the Congress members from Colorado tell us and how does it compare with national data? The chart below shows the distribution of Colorado data broken down by gender. The differences between the two sets of data for the genders are not statistically significant (t = -0.74, p = 0.49). Based on this evidence, we can conclude that the disbursements to members from Colorado are similar to national data, with respect to gender differences. We also see that the data for female members from Colorado has a wider distribution around the median compared to the male members. For reference, it should be noted that Colorado had 5 male members and 2 female members in the 117th Congress.
The chart below shows the distribution of Colorado data broken down by party. The differences along party lines are not statistically significant (t = 1.149, p = 0.30). Based on this evidence, we can conclude that the disbursements to members from Colorado are not similar to national data with respect to party differences. We also see that the data for the Colorado Democratic members have a wider distribution around the median, compared to the Republican members. It should be noted that Colorado had 4 Democratic and 3 Republican members in the 117th Congress.
Conclusions
The differences between spending by male and female members of Congress are not statistically significant, which points to gender equality. On the other hand, the differences between members of the Democratic and Republican parties are statistically significant and align with the general public opinions about fiscal conservatism. The data for members from Colorado does not show statistically significant differences along gender or party lines. But, the Colorado data does show slightly more variability for females and Democrats compared to males and Republicans. More research needs to be done in order to analyze patterns for individual categories of disbursements, such as personnel compensation, travel, and so on.
