The latest National Defense Authorization Act, passed in late December, offered much about which to complain. But two pieces of pork barrel spending stand out.

First, in the latest iteration of an ongoing saga, Congress provided $120 million for the M1 Abrams tank. The problem is, the Army did not request money for the Abrams and has not requested money for the Abrams for several years. The Army has a surplus of M1s dating back to the Cold War. The money is instead there due to a multiyear lobbying effort to keep the production line running at the General Dynamics Land Systems (GLDS) plant in Lima, Ohio.

Similarly, the NDAA included $1.5 billion for the Navy to purchase 15 EA-18G Growlers, an electronic warfare plane. The Growlers, while a very capable combat aircraft, were not part of the Navy’s original request. Instead, they came to congressional attention through the service’s “unfunded priorities list.” In a bipartisan effort, Missouri Representatives Ann Wagner and Lacy Clay pushed for funding for the Growlers after Boeing threatened to shut down its production line near St. Louis.

As Gordon Adams recently described at Foreign Policy, Congress made room for this pork barrel spending by shifting operations and maintenance spending to the overseas contingency operations (OCO) account. Exempt from sequestration, OCO has become a slush fund that allows both Congress and the military to pursue parochial interests instead of prioritizing. As Adams explains,

For the last couple of years, the appropriators have discovered the true miracle of OCO — it is a safety valve that allows members to shift spending that would otherwise be in the base defense budget, making room in the base budget (under the caps) for things the members would like to put in, but for which there seemed to be no room.

OK, so what am I talking about? I am talking about the appropriators cutting Operations and Maintenance (O&M) spending in the base budget below what the administration asked for (which is bad because some of that money funds military readiness), but then shifting some of that money to the OCO budget (readiness restored!). O&M funds cover everything from readiness to training and education to military exercises, to buying fuel, to repairing equipment, to paying civil servants.

This practice has the short-term effect of unnecessarily inflating defense spending. But there are long-term consequences for national security that often go overlooked. Pork barrel spending has reduced the incentives for innovation in the defense industry. With companies able to lobby Congress to continue funding on unnecessary or outdated systems—with the implied or actual threat of lost jobs in congressional districts—weapon manufacturers have consistently underinvested in research and development. Why take on the risk and cost of developing a new product your sole customer might reject, when industry can ensure it is paid through political connections?

MIT scholars Harvey Sapolsky, Eugene Gholz, and Allen Kaufman noticed this practice increasing in the late 1990s, writing at the time: “Contractors make more money selling additional copies of a known product than by risking technological failures in developing new ones, so they lobby for extended production runs rather than research and development.” Spending on contractor preferences, rather than military priorities, turns the procurement process on its head.

There is bad news and good news for the future prospects of defense pork as the Pentagon’s budget decreases. The bad news is that, certain manufacturers are likely to redouble their lobbying efforts to ensure their share of reduced defense dollars is not eliminated, as was the case with GDLS and the Abrams. The good news is that some manufacturers are seeing R&D investments as a way to earn future contracts. Lockheed Martin, for instance has expanded its R&D budget in recent years by thirteen percent in 2013 and an additional five percent 2014.

Hopefully, more contractors will follow Lockheed’s example, and the resulting competition could spur the type of innovation the Department of Defense is seeking for its new offset strategy. And hopefully, Congress facilitates this effort by resisting the urge to push defense pork in an effort to use the Pentagon’s budget as a jobs program.