As noted above, Table 1 reports standard errors grouped only at the pair level.  examines in a recent paper the consequences of non-compliance with the interdependence of disturbances in several dimensions, with model models for the structural gravity of cross-sectional data and bilateral trade panels, if concluded. These authors conclude that ignoring multi-channel clusters leads to misleading conclusions about the relevance of preferential trade agreements of different types, since multi-tiered consolidation has a significant impact on standard errors in commercial cost variables. To address this problem, Table 2 presents the results of multi-level grouping that allow for a correlation in the notion of error in all possible cluster dimensions. The grouping clearly has no impact on point estimates. The results show that despite significant differences between the two types of standard errors (grouped standard errors are higher), all estimates of positives at the 1% meaning level remain statistically significant and all previous conclusions remain unchanged. Columns 3 to 5 show the results if we break down, in turn, the decoding of the PTA, the fake GATT or both depending on the group to which each trading partner belongs. Two comments are correct. First, in all cases and regardless of the type of standard errors considered, the results show a positive and statistically significant effect (at least 10%) for models of mutual agreements that will account for the impact on exports when developed countries are the target markets. Second, the statistically significant coefficient for non-reciprocal agreements in columns 3 to 5, when standard defects are linked to country pairs, loses statistical significance when standard defects are grouped repeatedly.
Secretary Hull`s first efforts were to reach reciprocal trade agreements with Latin American countries, a region considered crucial to U.S. trade and security, where rival powers (particularly Germany) have gained ground at the expense of American exporters. However, until September 1939, Hull was only able to negotiate agreements with three out of ten South American countries, because the trade agenda was opposed by Latin Americans, who opposed the most favoured national requirement to abandon all bilateral agreements with other countries.