Multi-dimensional research and quantitative evaluation of export potential of Dezhou smes to Central Asia based on multi-level regression model under the background of China-Kyrgyzstan-Uzbekistan Railway

Figure 1.

Figure 2.

Figure 3.

Test of variance inflation factor

Variables	VIF	1/VIF
PCGDP	1.524	0.656
InPOP	1.798	0.556
BORD	1.915	0.522
LANG	2.382	0.420
InDIS	3.263	0.306
TAF	1.241	0.806
INF	2.518	0.397
SHP	2.065	0.484
EOC	1.859	0.538
TF	1.752	0.571
WTO	1.603	0.624
FTA	1.731	0.578

The top five categories of products exported by China to the Central Asian countries

Country	2013				2022
	Product category quantity	Product code	Amount ($100 million)	Share (%)	Product category quantity	Product code	Amount ($100 million)	Share (%)
Kazakhstan	3442	870423	1.88	1.65	3410	620193	3.82	2.16
		730420	2.10	1.85		847193	3.82	2.16
		730519	2.48	2.18		950390	5.09	2.88
		640299	5.06	4.45		620293	6.41	3.63
		847120	6.57	5.78		852520	6.63	3.76
Kyrgyzstan	2608	611030	1.41	3.24	2725	620462	5.14	4.64
		630260	1.62	3.72		611030	5.72	5.17
		540752	1.85	4.25		620193	6.81	6.15
		600192	2.04	4.68		640299	6.87	6.20
		521019	2.37	5.44		620293	10.49	9.47
Tajikistan	1483	630260	0.48	2.59	2659	940540	0.44	1.85
		730830	0.49	2.64		621210	0.53	2.23
		640510	0.52	2.81		870899	0.62	2.61
		610423	0.60	3.24		721070	0.71	2.99
		701339	0.64	3.45		640299	0.95	4.00
Turkmenistan	1398	841510	0.29	2.59	1624	510820	0.17	2.35
		842139	0.35	3.12		852810	0.21	2.90
		848180	0.39	3.48		401120	0.24	3.32
		847120	0.44	3.92		300220	0.28	3.87
		730420	0.96	8.56		860210	0.36	4.97
Uzbekistan	2232	721049	0.68	2.61	3341	852810	0.95	1.19
		730420	0.68	2.61		870323	0.96	1.20
		721070	0.75	2.88		390760	1.15	1.44
		730511	0.76	2.92		870390	1.48	1.85
		730519	1.94	7.46		852520	2.66	3.33

Regression result

Variable	OLS	RE	SFA
			Time invariant	Time-varying
PCGDPit	1.174***	0.895***	1.132***	0.984***
PCGDPjt	0.886***	1.114***	0.998***	0.875***
InPOPit	-11.208	-12.319***	-11.526***	-13.914***
InPOPjt	1.257**	1.406**	0.683**	0.878***
InDISij	-0.643***	-0.347	-0.012	-0.514***
BORDij	1.625***	1.434***	1.538***	1.296***
cons	231.742	265.839	273.824***	274.521***
μ	-	-	0.615	1.498
σ2	0.862	1.157	1.483	2.106
η	-	-	-	0.024***
γ	-	-	0.857	0.915
Logarithmic likelihood value	-	-	-501.365	-582.419
LR				154.257
Sample size	800	800	800	800

Parameter estimation result

	Variable	Coefficient	T-statistic
Random frontier gravity model	β0	261.415*	28.436
	PCGDPit	1.048***	-8.82
	PCGDPjt	0.756***	26.034
	InPOPit	-12.035***	-15.87
	InPOPjt	0.765***	-2.538
	InDISij	-0.514***	4.885
	BORDij	0.736**	-18.059
	η	0.021***	24.958
Trade inefficiency model	α0	1.026***	-1.105
	TAFjt	3.247***	-1.245
	INFjt	-1.466***	-2.034
	SHPjt	-0.518***	-2.653
	EOCjt	-3.525***	-4.516
	TFjt	-0.067***	-4.948
	WTOijt	-1.965**	-5.137
	FTAijt	-1.829*	-15.073
Reference quantity	σ2	1.584
	γ	0.675
	Logarithmic likelihood value	-1185.639
	LR	117.241

Results of SFA model applicability test

Original hypothesis	Constraint model	Unconstrained model	LR	1% critical value	Conclusion
There are no trade inefficiencies	-1542.36	-1076.43	985.92	9.34	Refuse
Non-efficient terms do not have time variability	-571.24	-502.49	120.45	10.61	Refuse
The variable BORD is not introduced	-471.28	-505.64	-82.47	10.48	Refuse
The variable LANG is not introduced	-541.35	-516.03	57.24	10.48	Can’t refuse

China’s exports to the five Central Asian countries from 2013 to 2023

Country	2013	2015	2017	2019	2021	2023
Kazakhstan	113.67	80.09	102.35	114.35	130.87	248.34
	53.36%	48.58%	51.44%	46.60%	48.22%	40.21%
Kyrgyzstan	43.58	35.94	50.24	58.63	63.76	197.46
	20.46%	21.80%	25.25%	23.89%	23.49%	31.97%
Tajikistan	18.54	18.06	13.27	15.16	15.85	37.39
	8.70%	10.96%	6.67%	6.18%	5.84%	6.06%
Turkmenistan	11.22	8.41	3.89	4.24	5.01	9.88
	5.27%	5.10%	1.95%	1.73%	1.85%	1.60%
Uzbekistan	26.01	22.36	29.23	53.1	55.93	124.47
	12.21%	13.56%	14.69%	21.60%	20.60%	20.16%
Total	213.02	164.86	198.98	245.39	271.42	617.54
	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%

Applicability test results of trade inefficiency model

Original hypothesis	Constraint model	Unconstrained model	LR	1% critical value	Conclusion
The variable TAF is not introduced	-178.48	-505.64	78.95	10.48	Refuse
The variable INF is not introduced	-178.48	-516.03	132.16	10.48	Refuse
The variable SHP is not introduced	-178.48	-140.57	74.59	10.48	Refuse
The variable ECC is not introduced	-178.48	-129.46	97.34	10.48	Refuse
The variable TF is not introduced	-178.48	-87.39	181.21	10.48	Refuse
The variable WTO is not introduced	-178.48	-116.58	124.68	10.48	Refuse
The variable FTA is not introduced	-178.48	-114.58	128.92	10.48	Refuse

Potential value of export trade and potential improvement space

Country	Kazakhstan		Uzbekistan		Kyrgyzstan		Tajikistan		Turkmenistan
Year	TP	TPIS	TP	TPIS	TP	TPIS	TP	TPIS	TP	TPIS
2013	466.72	330.47	325.59	285.13	807.17	637.94	102.44	91.28	56.32	50.54
2014	501.49	356.45	268.05	247.18	778.91	618.18	169.38	145.79	56.33	44.94
2015	442.25	297.93	410.38	347.55	1170.64	899.65	307.71	260.92	53.37	51.01
2016	542.16	350.4	350.75	299.96	1620.68	1204.2	642.69	536.83	98.66	89.15
2017	538.15	319.11	463.53	408.53	1586.11	1156.74	285.62	239.51	101.41	88.91
2018	543.71	309.68	477.53	409.69	1539.82	1079.04	180.18	141.5	92.3	79.96
2019	578.77	285.51	355.39	302.99	1603.54	1014.14	409.39	332.24	104.83	79.89
2020	631.22	282.64	408.13	349.44	1301.5	838.87	201.12	158.71	115.81	102.25
2021	549.31	213.71	280.24	239.62	1255.95	765.72	117.58	85.79	91.16	79.21
2022	596.3	190.87	361.06	307.2	625.3	352.61	124	97.92	99.99	91.28
2023	582.85	136.19	386.9	319.95	949.51	499.5	321.43	238.77	78.15	71.12