On the other hand, income support not based on current commodity production is much more effective at improving farm income with less spill-over effects. Policies that directly target non-commodity criteria such as landscape elements, environmental performance or traditional breeds of animals are also typically more effective at reaching these societal objectives, although concerns have been raised over the budgetary and transactions costs involved in some cases. Annual variations depend on movements in world prices, domestic prices and exchange rates as well as changes in production levels.