They note, however, that the impacts may vary considerably depending on the type of aid-for-trade intervention, the income level of the beneficiaries, the sector to which the support is directed and the geographical region of the recipient country. In the case of sectors, for example, Ferro et al. ( Cali and te Velde (2011) examined the impact of aid for trade on trade costs and exports, they found that a USD 1 million increase in aid-for-trade facilitation is associated with a 6% reduction in the cost of packing, loading and shipping to the transit hub. Busse et al (2012), using panel data on 99 developing countries covering the period 2004-09, show that aid for trade is closely associated with lowering trade costs, and therefore may play an important role in helping developing countries benefit from trade.