Background: The New York Public Library (NYPL) is a public library system in New York City. With nearly 53 million items and 92 locations, the New York Public Library is the second largest public library in the United States (behind the Library of Congress), and fourth largest in the world. It is a private, non-governmental, independently managed, nonprofit corporation operating with both private and public financing. The library has branches in the boroughs of Manhattan, The Bronx, and Staten Island, and affiliations with academic and professional libraries in the metropolitan area of New York State.
Context: The New York Public Library was not created by government statute. From its earliest days, the library was formed from a partnership of city government with private philanthropy. As of 2010, the research libraries in the system are largely funded with private money, and the branch or circulating libraries are financed primarily with city government funds. Until 2009, the research and branch libraries operated almost entirely as separate systems, but that year various operations were merged. By early 2010, the NYPL staff had been reduced by about 16 percent, in part through the consolidations.  In 2010, as part of the consolidation program, the NYPL moved various back-office operations to a new Library Services Center building in Long Island City. A former warehouse was renovated for this purpose for $50 million. In the basement, a new, $2.3 million book sorter uses bar codes on library items to sort them for delivery to 132 branch libraries. At two-thirds the length of a football field, the machine is the largest of its kind in the world, according to library officials. Books located in one branch and requested from another go through the sorter, which use has cut the previous waiting time by at least a day. Together with 14 library employees, the machine can sort 7,500 items an hour (or 125 a minute). On the first floor of the Library Services Center is an ordering and cataloging office; on the second, the digital imaging department (formerly at the Main Branch building) and the manuscripts and archives division, where the air is kept cooler; on the third, the Barbara Goldsmith Preservation Division, with a staff of 10 (as of 2010) but designed for as many as 30 employees.  The NYPL maintains a force of NYC special patrolmen, who provide security and protection to various libraries, and NYPL special investigators, who oversee security operations at the library facilities. These officials have on-duty arrest authority granted by the New York Penal Law. Some library branches contract for security guards.
Question: Why were they merged?

Answer:
By early 2010, the NYPL staff had been reduced by about 16 percent, in part through the consolidations.