Today, a "Dear Colleague" letter is official correspondence sent by a Member, committee, or officer of the House of Representatives or Senate and that is widely distributed to other congressional offices. These letters are named for their the most common opening salutation—"Dear Colleague"—and are often used to encourage others to cosponsor, support or oppose legislation; collect signatures on letters; invite Members to events; update congressional offices on administrative rules; and provide general information. This report provides a comparative analysis of how the use of the e-"Dear Colleague" system in the House of Representatives has changed between the 111 th Congress (2009-2010) and the 113 th Congress (2013-2014). To evaluate the overall volume of dear colleague sent since 2003, the first dataset, which contains the total number of "Dear Colleague" letters sent electronically between January 2003 and December 2014, was utilized. In all cases, the data do not include paper "Dear Colleague" letters or electronic "Dear Colleague" letters that were not sent through the House's email "Dear Colleague" system or the e-"Dear Colleague" system. Examining the number of electronic "Dear Colleague" letters sent each year provides an overall picture of the increased use of email- and web-based distribution to send "Dear Colleague" letters. In both the 111 th and 113 th Congresses, the most popular category was healthcare (8.8% and 8.3%, respectively). This was followed by foreign affairs (7.9%; 6.9%) in both congresses. In the 111 th Congress, education (6.0%) was third most popular followed by family issues (5.8%). For the 113 th Congress, family issues was third most popular (6.1%), followed by education (5.5%). For the data from the 111 th Congress, five categories were utilized:
1. solicited cosponsors for legislation 2. collected signatures for letters to executive branch officials or congressional leadership 3. invited other Members and staff to events 4. provided information or advocated on public policy, floor action, or amendments 5. announced administrative policies of the House
For letters from the 113 th Congress, the initial five categories were expanded into seven categories by dividing the invitation and information categories to better capture the content of "Dear Colleague" letters. Cosponsorship

Soliciting cosponsors for bills and resolutions was the most common reason for sending "Dear Colleague" letters in both the 111 th Congress (53.0%) and the 113 th Congress (42.0%). In the 113 th Congress, the number of letters asking for signatures increased to 25.4%. Information

Members, committees, and commissions also use "Dear Colleague" letters to provide information to other Members. In the 111 th Congress, administrative "Dear Colleague" letters accounted for 1.2% of letters in the database. Questions for Congress

Since the adoption and implementation of the e-"Dear Colleague" system in August 2008, the number of "Dear Colleague" letters sent in the House has continued to increase. In light of the analysis of the volume, use, characteristics, and purpose of "Dear Colleague" letters, several possible administrative and operations questions could be raised to aid the House in future discussions of the e-"Dear Colleague" system. As it currently stands, the e-"Dear Colleague" system is searchable by sender, letter title, and self-selected issue category. In 2003, 5,161 "Dear Colleague" letters were sent by email. This report analyzed the number of "Dear Colleague" letters sent and showed that, overall, the volume of letters sent continues to rise. In the 113 th Congress, those letters accounted for 30.9% of all letters sent.
The practice of one Member, committee, or office broadly corresponding to other Members, committee, or officers dates back to at least the 1800s. At least as early as 1913, this correspondence was labeled as "Dear Colleague" letters. Since 2003, it has been possible to track the volume of House "Dear Colleague" letters sent through an email-based distribution system (from 2003 to 2008) and a web-based distribution system (since 2008). The creation of the web-based e-"Dear Colleague" distribution system in 2008 has made it possible to systematically examine "Dear Colleague" letters, thereby offering a clearer understanding of what are largely, but not exclusively, intra-chamber communications.
Named for their opening salutation, "Dear Colleague" letters are official correspondence widely distributed to congressional offices. Members, committees, and officers of the House of Representatives often use "Dear Colleague" letters to encourage others to cosponsor, support, or oppose legislation. Additionally, senders use these letters to collect signatures, invite members to events, update congressional offices on administrative rules, and provide general information.
In analyzing data on the volume of "Dear Colleague" letters sent between January 2003 and December 2014 in the House of Representatives, several discernable trends can be observed. Overall the total number of "Dear Colleague" letters continued to increase from 5,161 letters sent in 2003 to 40,487 letters sent in 2014. Additionally, examining data from the web-based e-"Dear Colleague" system from the 111th Congress (2009-2010) and the 113th Congress (2013-2014) shows that the most common reason "Dear Colleague" letters are sent is to solicit cosponsorships for legislation. These cosponsor "Dear Colleague" letters accounted for 53.0% of letters in the 111th Congress and 42.0% in the 113th Congress. The second most frequent category in both congresses was asking for signatures for letters to congressional leadership, the President, or executive branch officials. These letters accounted for 20.8% of all letters in the 111th Congress and 25.4% in the 113th Congress.
Each "Dear Colleague" letter can be tagged in the electronic system with up to three self-selected policy categories. Analysis of the self-selected categories shows that the broad public policy issues that were most frequently tagged in the 111th Congress remained similar in the 113th Congress. Healthcare was the most frequently selected issue category with 8.8% of letters in the 111th Congress and 8.3% of letters in the 113th Congress. In both congresses, the next most popular category was foreign affairs (7.9% and 6.9%, respectively). In the 111th Congress, education (6.0%) was third most popular followed by family issues (5.8%). For the 113th Congress, family issues was third most popular (6.1%), followed by education (5.5%).
In light of the analysis of the volume, use, characteristics, and purpose of "Dear Colleague" letters, several possible administrative and operational questions are raised in this report to aid the House in future discussion of the electronic "Dear Colleague" system. These include questions on handling the growth in volume of "Dear Colleague" letters sent per year, and the potential to create additional mechanisms within the e-"Dear Colleague" system to aid subscribers in managing the "Dear Colleague" letters they receive.
For a brief explanation of how to send "Dear Colleague" letters, see CRS Report RL34636, "Dear Colleague" Letters: Current Practices, by Jacob R. Straus.