The way staff are deployed within an organization may reflect the missions and priorities of that organization.

In Congress, employing authorities hire staff to carry out duties in Member office, committee, leadership, and other settings. The extent to which staff in those settings change may lend insight into the Senate's work over time. Some of the insights that might be taken from staff levels include

• an understanding of the division of congressional work between Senators working individually through their personal offices, or working collectively, through committee activities;
• similar divisions of labor between committee and leadership settings, which could have implications for the development and consideration of legislation, the use of congressional oversight, or deployment of staff; and
• the extent to which specialized chamber administrative operations might have grown over time.

This report provides staffing levels in Senators', committee, leadership, and other offices since 1977.¹ No Senate resource appears to provide a publicly available, official, and authoritative count of the actual number of staff working in the chamber by office or entity. Data presented here are based on staff listed by chamber entity (offices of Senators, committees, leaders, officers, officials, and other entities) in Senate telephone directories. Figure 1 displays overall staffing levels in the Senate.

Table 1 in the "Data Tables" section below provides data for all staff listed in chamber directories in the Senate through 2022.

Senate Staffing

Senate Staff Data Collection

Data compiled for this report are based on a count of staff listed in the Senate telephone directories published since 1977.² Like most sources of data, telephone directory listings have potential benefits and potential drawbacks. Telephone directories were chosen for a number of reasons, including the following:

• telephone directories published by the Senate are an official source of information about the institution that are widely available;
• presumably, the number of directory listings closely approximates the number of staff working for the Senate;
• while arguably not their intended purpose, the directories provide a consistent breakdown of Senate staff by internal organization at a particular moment in time;³ and
• the directories afford the opportunity to compare staff levels at similar moments across a period of decades.

At the same time, however, data presented below should be interpreted with care for several reasons, including the following:

• There is no way to determine whether all staff working for the Senate are listed in the chamber's telephone directories. If some staff are not listed, relying on telephone directories could lead to an undercount of staff.
• Staff working in Senators' state offices were not listed until 1987. This could result in an undercount of staff, and makes comparisons pre-1987 and post-1987 difficult.
• It is not possible to determine if staff who are listed were employed by the Senate at the time the directories were published. If the directories list individuals who are no longer employed by the Senate, then relying on them could lead to an overcount of staff.
• The extent to which the criteria for inclusion in the directories for the Senate have changed over time cannot be determined. Some editions of the directory do not always list staff in various entities the same way. This may raise questions regarding the reliability of telephone directory data as a means for identifying congressional staff levels within the Senate over time.
• Some Senate staff may have more than one telephone number, or be listed in the directory under more than one entity.⁴ As a consequence, they might be counted more than once. This could lead to a more accurate count of staff in specific entities within the Senate, but multiple listings may also lead to an overcount of total staff working in the chamber.
• Chamber directories may reflect different organizational arrangements over time for some entities. This could lead to counting staff doing similar work in both years in different categories, or in different offices.

Senate Staff Data

It appears that the Senate telephone directories started listing Senate staff working in Senators' state offices in 1987. Given the lack of consistent staff data from Senators' offices prior to 1987, comparisons between data from those offices from 1977-1986 and 1987-2022, as well as any analysis of total staffing levels in the Senate before 1987, would be incomplete. Staff levels from committees, leadership, and officers and officials, however, can be evaluated across the entire 1977-2022 time period. Analysis of total staffing levels, as well as staff distribution, since 1987 is discussed below.

In the Senate, the number of staff has grown steadily, from 4,916 in 1987 to 6,019 in 2022, or 22.44%. Each year since 1987, the number of Senate staff has grown by an average of 33 individuals.⁵ From 1977 to 1986, excluding congressional staff from state offices, the number of staff in the Senate grew steadily from 3,397 in 1977 to 4,180 in 1986, or 23.05%. Figure 1 displays staff levels for Senators' staff, including Washington, DC- and state-based staff; committees; leadership; and officers and officials since 1977.

Table 1 in the "Data Tables" section, below, provides detailed staff levels in those categories.

Figure 1. Senate Staff Levels by Category, 1977-2022

Source: Senate telephone directories, CRS calculations. Notes: Data exclude Senate staff working for the President of the Senate and the President Pro Tempore. The Senate did not publish a directory in 2019 and published a directory covering 2021-2022 in 2022.

Staff in Senators' Offices

Staff in Senators' offices grew from 2,068 in 1977 to 2,474 in 1986, or 19.63%. Due to the addition of staff data in Senators' state offices to the telephone directories beginning in 1987, comparisons of total staff before 1986 are not possible, but staff in Senators' Washington, DC, offices continued to grow. In 2022, there were 2,507 staff in Senators' DC offices, and in 1977, there were 2,068, an increase of 21.23%. Staff in Senators' offices, including state-based staff, have grown from 3,286 in 1987 to 4,162 in 2022, an increase of 26.66%. In 1987, Member-office staff comprised 66.84% of overall Senate staff. The average proportion between 1987 and 2022 is 61.85%.

Most of the growth in Senators' staffs since 1987 appears to have been among state-based staff, which nearly doubled in size from 935 in 1987 to 1,655 in 2022. More staff work in Washington, DC, offices than in state offices, but the percentage of Senators' staff based in states has grown steadily since 1987, while the number of staff in Senators' Washington, DC, offices has remained relatively flat. In 2022, 60.24% of staff listed in the Senate telephone directory as working in Senators' offices did so in Washington, DC, down from a high of 72.18% in 1988. Table 2 in the "Data Tables" section below provides the number of staff working in Senators' offices in Washington, DC, and state offices.

Committees

Senate committee staff levels have shown the smallest change among Senate staff categories, increasing from 1,084 in 1977 to 1,194 in 2022, or 10.15%. Change among Senate committee staff may be characterized in five stages: an increase during 1977-1980 (20.57%); a period of decline in 1980-1999 (-27.93%); a period of growth from 1999 to 2011 (33.97%); a decline in 2011-2013 (-11.57%); and growth from 2014 to 2022 (5.57%).

Between 1987 and 2020, committee staff comprised a decreasing proportion of Senate staff, falling from a peak of 23.39% of Senate staff in 1987 to a low of 17.49% of staff in 1995. The proportion of Senate committee staff grew to 19.80% in 2022.

In the "Data Tables" section below, Table 3 provides staff levels in various Senate committees for 2013-2022. Committee staff data since 1977 are available to congressional staff upon request.

Leadership Offices

The number of staff in Senate leadership offices grew from 44 in 1977 to 191 in 2022. Most of the growth in leadership staff occurred between 1977 and 1981, from 44 to 119, or 170.45%. The number of leadership staff peaked in 2012 at 234. Leadership employees were 2.69% of overall Senate staff in 1987 and 3.20% in 2022.

Officers and Officials

Staff working in the offices of Senate officers and officials has increased 132.34% since 1977. Staff levels have grown from 201 in 1977 to 467 in 2022, but were characterized by sharp decreases in 1988, from 1998 to 2001, in 2012, and in 2016. Increases were observed in 2013, 2018, 2020, and 2022. In 2022, the proportion of officers and officials' staff was 7.76%.

Presiding Officers

The smallest category of staff includes those working in the Senate for the President of the Senate and the President Pro Tempore. Staff in those offices ranged from a high of 14 in 1981 to a low of 3 in 2013 and 2014. The average number of staff in the Senate offices of presiding officers between 1977 and 2022 was nine.

Discussion

Since 1987, the number of staff working for the Senate has grown. There have been increases in the number of staff working in Senate leadership offices, and larger increases in the staffing of officers and officials. Staff working for Senators have shifted from committee settings to leadership settings or Member offices. Some of these changes may be indicative of the growth of the Senate as an institution, or the value the chamber places on its various activities.

One example that may arguably indicate institutional development is found in the growth of the number of staff working in the offices of leadership, officers, and officials. A potential explanation for this change may be found in what some might characterize as an ongoing professionalization and institutionalization of congressional management and administration. Some note that as organizations such as governing institutions develop, they identify needs for expertise and develop specialized practices and processes. In Congress, some of those areas of specialization arguably include supporting the legislative process through the drafting of measures, oversight and support of floor activities, and the management of legislation in a bicameral, partisan environment. Another potential explanation related to a more institutionalized, professionalized Congress could be increased demand for professional management and support. This could arise as a result of congressional use of communications technologies, and the deployment of systematic, professionalized human resources processes, business operations, and financial management. Increased specialized support of congressional legislative and administrative activities may explain increases among staff working for chamber leaders, and officers and officials.

In another example that may indicate changes in the value the chamber places on various activities, the distribution of staff working directly for Senators has shifted from committee settings to personal office settings. Staff in Member offices has grown while staff in Senate committees has decreased, both in real numbers and in percentage of total staff. This may represent a shift from collective congressional activities typically carried out in committees, including legislative, oversight, and investigative work, to individualized activities typically carried out in Senators' personal offices, including direct representational activities, constituent service and education, and political activity.

Data Tables