for which cross-border trade is the main source of income.<sup>16</sup> We then check whether CTA adoption influences monthly per-capita spending<sup>17</sup> and monthly per-capita income. The results reported in Table 4 show that the impact of CTA adoption on Household income is positive and significant. The CTA adoption is associated with an increase in monthly household expenditures of more than 20% and an increase in monthly household income of more than 30%, regardless of whether cross-border trade is the primary source of household income. These numbers are the average change in per capita expenditure and per capita income of households that belongs to a change in trade status.

To corroborate this significant impact, we applied two additional treatment effect models, namely the propensity score matching (PSM) and the Nearest-neighbor matching techniques (NNM). The result reported in Table 7 give an ATE and an ATT for the two methods (PSM and NNM) applied on the two household outcomes (Spendings and 4. Income), are positives and significant.This confirms the results of LATEs estiators from We also follow the method proposed by Oster (2019) to investigate whether these results on household outcomes could be driven by unobservable factors. Using the technique explained in the section 4.2, we find that the corresponding deltas in Table 8, Panel 2 imply that to explain away the impact in columns 2 and 4, unobservables would have to move the coefficient in the opposite direction as observables, and their influence would have to be more than three ( _δ_ in columns 2) and four ( _δ_ in columns 4) times as large for spendings and income respectively. Taken together, the results in Table 8, Panel 2 thus strongly suggests that omitted variable bias is not driving our results.

Table 4: LATE estimates of the Effects of CTA adoption on SSCBT’s household Income

|Outcome|Monthly per c|apita spendings|Monthly per|capita income|
|---|---|---|---|---|
||Full sample|Main source<br>of income|Full sample|Main Source<br>income|
|CTA adoption|0.221***|0.217***|0.307***|0.328***|
||(0.084)|(0.085)|(0.104)|(0.104)|
|Observations|1084|1029|1089|1029|
|F Statistics (excluded instruments)|792.25***|885.98***|793.48***|791.34***|
|Under identifcation test p value|0.0000|0.0000|0.0000|0.0000|
|Wald test (joint signifcance)|6.90***|6.51***|8.64***|9.84***|
|Cragg-Donald Wald F|358.89|351.10|360.73|352.13|
|Stock-Yogo : critical values|(16.38)|(16.38)|(16.38)|(16.38)|

Notes: outputs are log-transformed. ***,**,* Denote significance at 1%, 5% and 10% levels, respectively. Standard errors are in parenthesis. Socio-demographic Controls includes variable such as Head of Household, gender, Age, Education, Living in urban, Experience as SSCBT, Dependency ratio, whether the partner has a Job, the logarithm of purchased volume amount (a proxy of SSCBT’s capital) and the dummy for Province

> 16Descriptive evidence in Table 1 shows that for 94.82% of our sample, the cross-border trade is the main source of household income.

> 17These items include all food consumption; non-food consumption items were restricted to direct consumables (matches, soap, linen, and clothes), school and health expenditure, as well others contributions.

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