Trade Capacity

This study addresses the short-and long-term effects of infrastructure on exports and trade deficits in certain South Asian countries between 1990-2017. As you read, think about other countries where limited infrastructure capacity has affected their ability to develop.

Empirical results and discussions

Prior to observing the potential long- and short-run impact of infrastructure on export and trade deficit, it is essential to create the order of integration among the selected variables because if the variable(s) are integrated of order I(2) the results do not remain valid. For this reason, Levine et al. and Im et al.  unit root tests are employed to examine the order of integration among the chosen variables. The results in Table 2 point out that all variables are either integrated of order I(1) or I(0) and no one of the variables is integrated of order I(2) or above, which clearly support the Pooled Mean Group (PMG) estimation procedure rather than other alternative cointegration technique.

Table 2 Unit root test results

  Level First difference
Levin Lin Chu test IM Pesaran test Levin Lin Chu test IM Pesaran test
Export 0.941 − 0.118 − 3.403*** − 3.029***
Trade deficit − 1.185** − 0.802 − 4.249*** − 4.688***
Human capital 1.089*** 0.456*** − 4.638*** − 4.478***
Exchange rate 0.070 0.534 − 4.402*** − 3.762***
Per capita GDP 0.454 0.761 − 4.139*** − 3.211***
Institutional quality − 5.636*** − 4.804 − 3.226*** − 3.143***
Transport infrastructure − 2.668*** − 2.377*** − 7.752*** − 8.063***
Telecommunication infrastructure − 1.801*** − 2.286** − 4.253*** − 6.180***
Energy infrastructure − 1.274*** − 2.761*** − 4.585*** − 4.604***
Financial infrastructure 0.176*** − 1.593* − 2.049*** − 4.661***
Aggregate infrastructure − 2.142*** − 2.328*** − 6.001*** − 7.297***

****, ** and * denote the significance at 1%, 5%, and 10%, respectively. All variables are in natural log form. The results are based on intercept and trend


The descriptive statistics of the explanatory variables is shown in Appendix 2. Appendix 3 presents the Pearson correlation coefficients among all the selected variables of the present study. It can be seen from Appendix 2 that there is strong positive correlation between the export and all others explanatory variables. On the other hand, there is a strong negative correlation between trade deficit and all other independent variables. In the subsequent regression, in order to alleviate the interference of multicollinearity on the regression results, there is no multicollinearity problem in our selected variables.

The empirical results in Table 3 show the outcomes of the PMG heterogeneous panel procedure. The result exhibits notable variations subject to the method of estimation. The PMG estimation result shows that a plausible long-run impact of aggregate and sub-indices of infrastructure (transport, telecommunication, energy, and financial sector) on export is positive and significant at 1% level in selected South Asian economies. The significant role of aggregate and all other sub-indices of infrastructure in exports confirm the findings of Donaubauer et al. and Brooks and Menon. Thus we reject the null hypothesis of no impact of independent variables on dependent variables, rather we accept alternative hypotheses. The empirical results are consistent with the opinion that, infrastructure matters to trade mainly because they decrease the cost of trade and ensure the ease of doing business in host economies. Lower trade costs raise the potential for increased export markets. This study uses the South Asian economies which are less developed countries. So, Garsous argues that the larger the number of developing countries in the sample, the more likely a positive impact of infrastructure on trade is likely to be observed. This would lead to the conclusion that the less developed the country, the more likely infrastructure will matter. Andrés et al. and Asif and Rehman found that infrastructure development has been a main determinant in reducing Asia's trade costs and thereby export expansion. Among the infrastructure the effects of other control variables, i.e., exchange rate (ln_EXR), human capital (ln_HC), per capita GDP (ln_PGDP), institutional quality index (ln_IQ) on exports is significant in all columns. It indicated that the undermentioned control variables increase the export significantly, except exchange rate which is consistently negative and significant in the present results. It presents that, when the  exchange rate of a host economy increases, automatically the price seems to be high. So export will decrease. The results are in the line of Sahoo and Dash and Ayogu. Similarly, institutional quality has a significant positive impact on export. It signifies that better quality of institutions significantly encourage export in the domestic economy. These empirical results negate the claim of Khan et al. that institutional quality does not contribute to export in South Asian economies. Furthermore, it can be seen in the lower half of Table 3, that in the short run, most independent variables are insignificant except aggregate infrastructure (ln_GINFRA), which is significant in both the short and long run.. The values of ECT(−1) in Table 3 show slow adjustment to equilibrium position by exports. Likewise, in the present study, most of the developing countries experience persistent low economic growth; it is very likely that such a long-run relationship exists. However, there is little evidence to suggest their speed of adjustment to the long-run steady state should be the same.

Table 3 Pooled Mean Group method results (export is dependent variable)

Variables Transport infrastructure Telecommunication infrastructure Energy infrastructure Financial infrastructure Aggregate infrastructure
Long-run results
 Exchange rate − 3.0573*** − 0.5454*** − 0.1234* − 1.4267*** − 0.7673**
 Std. error 0.6979 0.0269 0.0994 0.3677 0.3298
 Human capital 0.1536 1.5653*** 0.1917* 0.1418 0.1670
 Std. error 0.3075*** 0.1994 0.1175 0.5383 0.4494***
 Per capita GDP 1.7352 0.8590*** 0.5565*** 1.4300*** 1.0565
 Std. error 0.2093 0.013 0.0386 0.2013 0.2349
 Institutional quality 1.6017*** 0.0531*** 0.1887* 0.9098*** 0.4234***
 Std. error 0.5920 0.0219 0.1171 0.1538 0.0513
 Transport infrastructure 1.3117***        
 Std. error 0.4232        
 Telecommunication infrastructure   0.4720***      
 Std. error   0.0155      
 Energy infrastructure     0.7733***    
 Std. error     0.2598    
 Financial infrastructure       0.2549***  
 Std. error       0.0628  
 Aggregate infrastructure         0.3267***
 Std. error         0.0878
Short-run results
 Exchange rate − 0.5190 − 0.0306 − 0.1256 − 0.4713 − 0.5334
 Std. error 0.4602 0.1472 0.2514 0.2414 0.4803
 Human capital 0.0592 0.9343 0.2223 0.1845 0.1577
 Std. error 0.1673 0.8129 0.4239 0.1946 0.2007
 Per capita GDP 2.1747* 0.3917 0.9911*** 1.0156 0.9119***
 Std. error 1.2822 0.3526 0.1564 0.1227 0.3089
 Institutional quality 0.1410 0.1099 0.0890 0.0864 0.3214**
 Std. error 0.4021 0.0770 0.2367 0.1373 0.1544
 Transport infrastructure 0.0773        
 Std. error 0.1899        
 Telecommunication infrastructure   0.2901      
 Std. error   0.1239      
 Energy infrastructure     0.0853    
 Std. error     0.3017    
 Financial infrastructure       0.0494  
 Std. error       0.0509  
 Aggregate infrastructure         0.0874**
 Std. error         0.0489
 Constant − 0.2699 1.7603 0.9300 − 0.6134 − 0.9540
 Std. error 0.6757 1.6136 0.5594 0.7883 0.1231
 ECT(−1) − 0.2954* − 0.3867** − 0.2478** − 0.1220** − 0.2429***
 Std. error 0.1496 0.2183 0.1421 0.0671 0.0683
 Hausman test (P-values) 0.4886 0.9995 0.2896 0.0063 0.4585
 Pearson CD test (P-values) 0.2679 0.4855 0.2749 0.3271 0.6453
****, ** and * denote the significance at 1%, 5%, and 10%, respectively. Control variables are the same in each regression. In order to decide between PMG and MG estimator, this study employed the Hausman test. Hausman test results confirmed the PMG in all columns. The Pearson CD test presents that there is no problem of cross-sectional dependency.

On the other hand, the outcomes of PMG technique in Table 4 confirm the long-run effect of aggregate and all other sub-indices of infrastructure on trade deficit in selected South Asian economies. Thus we reject the null hypothesis of no impact of independent variables on dependent variables.  So, in this case, we also accept an alternative hypothesis. The results are supported by the study of Ahmad et al. and Brooks and Menon. Our empirical results are consistent with the idea that better infrastructure decreases the trade costs and alters the comparative advantages of a country, making greater fragmentation of production supply chains possible and spurring the country's international trade. Taking the example of Rehman et al. and Escribano et al., a reduction in transport and communication costs by 10% each would increase trade by about 6% and also 1% increase in aggregate infrastructure investment increases exports by about 0.6% and imports by about 0.3% in developing countries. This shows that availability of infrastructure increases exports more than imports. That is why the coefficient of aggregate infrastructure (Ln_GINFRA) and sub-indices including transport (Ln_TINFRA), telecommunication (Ln_CINFRA) and energy (Ln_EINFRA) sector is negative and significant at 1%. Our selected South Asian countries have huge trade deficits (imports > exports) from the last two decades. The empirical results of this study signifies that better quality and availability of aggregate and chosen sub-indices of infrastructure encourage more export which will obviously decrease trade deficit in selected economies of south Asia.

Table 4 Pooled Mean Group estimator results (trade deficit is dependent variable)

Variables Transport infrastructure Telecommunication infrastructure Energy infrastructure Financial infrastructure Aggregate infrastructure
Long-run results
 Exchange rate − 0.8650*** − 0.6846** − 0.8017*** − 4.1071*** − 3.4787***
 Std. error 0.2376 0.3581 0.2989 0.4929 0.7478
 Human capital − 0.0136 − 0.1006 − 0.0305 − 1.3230* 0.7265*
 Std. error 0.2848 0.3298 0.3390 0.8826 0.4233
 Per capita GDP 1.3501*** 1.3395*** 1.3543*** 3.0160*** 2.7465***
 Std. error 0.1807 0.1735 0.1348 0.3011 0.6561
 Institutional quality − 0.2859 − 0.6712** − 0.5844*** 0.7035 1.5687***
 Std. error 0.2488 0.3039 0.2682 0.7742 0.3632
 Transport infrastructure − 0.1078**        
 Std. error 0.0554        
 Telecommunication infrastructure   − 0.0464      
 Std. error   0.1958      
 Energy infrastructure     − 0.0247    
 Std. error     0.1032    
 Financial infrastructure       0.3237***  
 Std. error       0.0802  
 Aggregate infrastructure         − 0.4292***
 Std. error         0.1751
Short-run results
 Exchange rate 2.5839*** 2.2407** 2.5519*** 2.5864 4.3304
 Std. error 0.1816 0.7701 1.0489 1.6439 2.9042
 Human capital 0.0903 0.3284*** 0.0070 − 0.9086 0.9416
 Std. error 1.4475 0.1039 1.3530 1.5923 0.8382
 Per capita GDP 3.3435*** 3.3054*** 3.5189*** 3.0206** 1.3757
 Std. error 1.1054 0.7950 1.0498 1.4649 0.4562
 Institutional quality − 1.6697 − 1.1406 − 1.4167 − 0.6815 − 1.6054
 Std. error 1.4140 1.1943 1.2166 0.9362 0.6058
 Transport infrastructure 0.2748        
 Std. error 0.3606        
 Telecommunication infrastructure   − 0.5274**      
 Std. error   0.2918      
 Energy infrastructure     − 0.2832    
 Std. error     0.3510    
 Financial infrastructure       0.0257  
 Std. error       0.0802  
 Aggregate infrastructure         0.0113
 Std. error         0.1587
 Constant − 0.7986*** − 0.5983*** − 0.6599*** 0.9704* − 1.3201
 Std. error 0.1693 0.2918 0.1424 0.6286 1.7275
 ECT(−1) − 0.436*** − 0.3745*** − 0.4001*** − 0.3108* − 0.6665**
 Std. error 0.181 0.1707 0.1622 0.2096 0.2864
 Hausman test (P-values) 0.8237 0.987 0.8060 0.2345 0.986
 Pearson CD test (P-values) 0.8372 0.5491 0.4414 0.6660 0.5327
****, ** and * denote the significance at 1%, 5%, and 10%, respectively. Control variables are the same in each regression. In order to decide between PMG and MG estimator, this study employed the Hausman test. Hausman test results confirmed the PMG in all columns. The Pearson CD test presents that there is no problem of cross-sectional dependency

In addition to that, the effect of other control variables such as exchange rate, human capital per capita GDP, institutional quality index is significant and negative in most of the columns except human capital which has the correct sign according to economics theory but insignificant. It is due to the fact that selected South Asian economies have insufficient human capital (i.e., decrease rate of enrollment in secondary school) and imports continuously rise up which may cause insignificancy. One can examine the empirical results of Table 3, that the influence of human capital on export is positive and significant. It is due to the reason that export enhances relative to the speed of human capital in South Asian economies, while in short run the influence of aggregate and all other sub-indices of infrastructure on trade deficit is insignificant. The values of ECT(−1) in Table 6 show slow adjustment to equilibrium position by trade deficit due to the above-mentioned reason.

Table 5 presents the Pedroni and Kao cointegration test results. The empirical results of Table 5 demonstrate the existence of a cointegration between dependent (i.e., export) and independent variables (such as ln_EXR, ln_HC, ln_IQ, ln_PGDP and ln_GINFRA) fully established in both (within-dimension and between-dimension) in all specifications because the v-statistic and the rho-statistics probability values are lower than the conventional level of significance, and also the ADF-statistic and PP-statistic indicate that their probability values are significant at 1% level of significance. The probability values of rho-statistic, v-statistic and ADF-statistic are also significant in case of trend and intercept (between-dimension and within-dimension). The PP-statistic (between-dimension and within-dimension) is significant at 1%, also ADF-statistic is significant at 1%.

Table 5 Pedroni and Kao cointegration test (export is dependent variable)

Export Within-dimension (Panel) Between-dimension (Group)
v-Statistic − 1.4074* 2.6440 Group-rho 2.4950***
rho-Statistic − 1.534* − 1.9146** Group-PP − 1.6704*
PP-statistic − 3.4253*** 0.6203 Group ADF − 1.9146**
ADF-statistic − 1.178* − 1.8524** Kao test − 2.22***

****, ** and * denote the significance at 1%, 5%, and 10%, respectively


We observed from the results of Table 5 that the cointegration is strong when an export use is a dependent variable in the analysis because most of the variables show significance (between-dimension, within-dimension and deterministic trend and intercept). Furthermore, Kao test in Table 5 clearly indicates that there is a long-run relationship between the dependent and independent variables in South Asian countries, because of the reason that all variables are significant. Here, we clearly reject the null hypothesis (of no cointegration) and accept an alternative hypothesis (presence of cointegration).

It can be seen from Table 6, this study also uses trade deficit as a dependent variable and apply Pedroni and Kao cointegration test. The results confirmed the presence of a cointegration fully conventional in both (within-dimension and between-dimension) in all specifications of v-statistics and rho-statistics because the v-statistic and the rho-statistics probability values are decreased than the conventional level of significance. The ADF-statistic and PP-statistic indicate that their probability values are significant at 1% level of significance. In the case of deterministic trend and intercept (between-dimension and within-dimension) the rho-statistics and v-statistics probability value shows significance at 1% level. The PP-statistic and ADF-statistics (between-dimension and within-dimension) is significant at 1%. We concluded from the results of Table 6 that the cointegration is also strong when the trade deficit used is a dependent variable in the regression analysis because most of the variables show insignificancy (between-dimension and within-dimension). Table 6 also shows the Kao cointegration test. The results show the dependent and independent variables are co-integrated, because whole variables are significant in all specifications.

Table 6 Pedroni and Kao cointegration test (trade deficit is dependent variable)

 Within-dimension (Panel)Between-dimension (Group)
v-Statistic1.852***− 1.7708**Group-rho0.159
rho-Statistic− 0.8120.868Group-PP− 2.214***
PP-statistic− 2.323***0.0472Group ADF− 2.204***
ADF-statistic− 1.526***0.548Kao test− 2.79***

****, ** and * denote the significance at 1%, 5%, and 10%, respectively