Despite this, comparisons between different sectors indicate that SPS and TBT arrangements may also foster trade - highlighting the difficultly in attempting to determine the distortions potentially created by such measures. In a similar vein, Winchester (2009) suggests that reforms to trading arrangements that only focus on tariff and other border measures will produce much smaller gains than if non-tariff barriers are included. For New Zealand, Winchester (2009) finds that welfare gains from agro-food trade reform including the elimination of non-tariff barriers was more than four times greater for a range of possible bilateral agreements than if only tariff barriers were removed.