It's not just the Federal government. State government agencies are like that too. If they have money left they feel they need to spend it or else they'll get shorted on their budget request for the next year. I worked as a Statistician for one State and as a Biologist for another and it was like that in both places.
Maybe the solution is to develop a culture at the legislative level that does not penalize them if they spend less then they were budgeted for the previous year. You know, when I do budget projections I always err on the side of more spending. Then at the end of the year I almost always have money left and can tell my organization they can take my leftover funds for someone else to use.
Maybe they could create a culture where it is understood that agencies are going to do something like that. They're going to make budget requests conservatively so as to make sure they have enough to cover whatever happens. Everybody understands that most of the time they are going to have funds left over at the end. But the legistlature does not penalize them by shorting them on their next budget request. They trust them to shepherd the funds wisely and even reward them for saving money.
