Table 6: Positive Ownership Counts: Vertical integration in Global Value Chains

|log(Number of Firm-to-Firm Connections (_CF _<sup>_rs_</sup><br>_ij,t_<sup>))</sup>|PTA|Total depth|Core depth|WTO-X depth|
|---|---|---|---|---|
|Backward<sup>_rs_</sup><br>_j_ <sup>(</sup><sup>_ars_</sup><br>_j,t_<sup>)</sup>|0_._017|_−_0_._031|_−_0_._013|_−_0_._046|
||(0_._104)|(0_._102)|(0_._103)|(0_._101)|
|Forward<sup>_rs_</sup><br>_j_ <sup>(</sup><sup>_brs_</sup><br>_j,t_<sup>)</sup>|0_._448<sup>_∗∗∗_</sup>|0_._407<sup>_∗∗∗_</sup>|0_._420<sup>_∗∗∗_</sup>|0_._406<sup>_∗∗∗_</sup>|
||(0_._111)|(0_._109)|(0_._110)|(0_._108)|
|PTA-Measures_ij,t_|0_._022<sup>_∗∗_</sup>|0_._045<sup>_∗∗_</sup>|0_._019<sup>_∗_</sup>|0_._065<sup>_∗∗_</sup>|
||(0_._010)|(0_._021)|(0_._012)|(0_._031)|
|PTA-Measures_ij,t ×_ Backward<sup>_rs_</sup><br>_j_|_−_0_._175<sup>_∗_</sup>|_−_0_._138|_−_0_._135|_−_0_._122|
||(0_._100)|(0_._136)|(0_._106)|(0_._155)|
|PTA-Measures_ij,t ×_ Forward<sup>_rs_</sup><br>_j_|0_._161<sup>_∗_</sup>|0_._372<sup>_∗∗∗_</sup>|0_._243<sup>_∗∗_</sup>|0_._467<sup>_∗∗∗_</sup>|
||(0_._095)|(0_._130)|(0_._101)|(0_._149)|
|BIT_ij,t_|0_._013|0_._013|0_._013|0_._013|
||(0_._011)|(0_._011)|(0_._011)|(0_._011)|
|Country-pair FE|✓|✓|✓|✓|
|Industry-pair FE|✓|✓|✓|✓|
|Shareholder-country-industry-year FE|✓|✓|✓|✓|
|Subsidiary-country-industry-year FE|✓|✓|✓|✓|
|Domestic-year FE|✓|✓|✓|✓|
|Obs.|990,033|990,033|990,033|990,033|
|R<sup>2</sup>|0.564|0.564|0.564|0.564|

Standard errors are clustered at country-industry pairs level and reported in parentheses. * _p <_ 0 _._ 1, ** _p <_ 0 _._ 05, *** _p <_ 0 _._ 01 Table 6 reports on the ownership-count effects of PTA-Measures _ij,t_ as such and interacted with the vertical-integration measures. The table is horizontally organized in four columns of results, where the first column is devoted to the binary measure of PTA and the rest to their depth.

The binary PTA indicator carries a positive (semi-elasticity) coefficient, and bigger interdependence in the forward integration direction also boosts the number of ownership links. However, we do not find evidence of a strong and robust interaction between PTA membership and the backward integration direction.

Whereas the first column of Table 6 did not acknowledge the heterogeneity of PTAs depending on their depth, we will do so in columns 2 to 4 by defining PTA-Measures _ij,t_ as to contain one of the elements in _{_ Total depth _ij,t,_ Core depth _ij,t,_ always used in the main effects as well as in the interactions with the GVC measures. These results suggest that PTA membership raises the number of ownership links, in particular, in the forward-integration direction. Moreover, forward integration becomes more attractive with deeper PTAs.

Next, we turn to the results regarding the propensity of any ownership links being formed where there were none prior to a PTA.

Table 7 is structured in the same way as Table 6, but it involves the binary ownership indicator as a dependent variable. The results suggest a relatively stronger influence of backward integration than of forward integration for the propensity of any ownership. When taking the main effects and the interaction terms together and evaluating the increase of GVC-Measures<sup>_rs_</sup> _i,t_<sup>inonestandarddeviation,theoverall</sup> 13