Study on the Characteristics and Evolution Trends of Global Uranium Resource Trade from the Perspective of a Complex Network

Round 1

Reviewer 1 Report

The paper is interesting and well-written. Anyway, there are several remarks, which has to be addressed:

1) the paper is based on historical data, what is conventional and relevant approach. Anyway, the further development of nuclear energy and respective trade in uranium will depend on political decisions. Please pay more attention to public perception of nuclear energy and a role of political decisions. One recommended source is provided below:

Genys, D., Krikštolaitis, R. 2020. Clusterization of public perception of nuclear energy in relation to changing political priorities. Insights into Regional Development, Insights into Regional Development, 2(4), 750-764. http://doi.org/10.9770/IRD.2020.2.4(2)

2) please express your opinion how a war of Russia against Ukraine can alter the trade in uranium. Your considerations would be very interesting to scientists and wider public.

 

 

Author Response

Author's Reply to the Review Report (Reviewer 1)

The paper is interesting and well-written. Anyway, there are several remarks, which has to be addressed:

 

1) the paper is based on historical data, what is conventional and relevant approach. Anyway, the further development of nuclear energy and respective trade in uranium will depend on political decisions. Please pay more attention to public perception of nuclear energy and a role of political decisions. One recommended source is provided below:

 

Dear Reviewers:

Thank you so much for your recommended source. And we have read this article and listed it in the references.

Genys, D., Krikštolaitis, R. 2020. Clusterization of public perception of nuclear energy in relation to changing political priorities. Insights into Regional Development, Insights into Regional Development, 2(4), 750-764. http://doi.org/10.9770/IRD.2020.2.4(2)

By the way, we added another article as well:

Benjamin K. Sovacool. 2016. Differing cultures of energy security: An international comparison of public perceptions. Renewable and Sustainable Energy Reviews, 55, 811-822. http://dx.doi.org/10.1016/j.rser.2015.10.144

It is referred in the paper:

There is no denying that the development of nuclear power will be affected by policy-making in the future (Benjamin et al., 2016; Genys, D. et al., 2020).

 

2) please express your opinion how a war of Russia against Ukraine can alter the trade in uranium. Your considerations would be very interesting to scientists and wider public.

 

The Russia-Ukraine conflict is one of the most important and influential geopolitical events.  in accordance with from UN Comtrade data in 2020, Ukraine is the ninth Uranium exporting country in the world, and all Uranium had been exported to Russia; meanwhile, Russia is the fourth Uranium importing country, and it imported mostly from Kazakhstan (86.14%), Ukraine (10.57%), and Canada (3.29%). Accounting for 43% of the global production, Russia is the largest Enriched Uranium exporter, mainly to the USA (43.53%), Sweden (27.1 %), Korea (15.96%), Germany (7.18%), and China (4.66%). With the development of the conflict, the Ukraine government would ban the export of Uranium to Russia. It will affect the Enriched Uranium export from Russia, and then this influence will spread to the USA, Sweden, Korea, Germany, and China. However, in order to be able to export the quantities, Russia has to increase the import value of Enriched Uranium from other countries, which will likely lead to uranium price upside.

At the same time, in order to end the dependency on Russian fossil fuels, many European countries proposed to invest in nuclear power. Belgium has decided to postpone its nuclear phase-out scheduled for 2025 by 10 years, worried about the soaring energy prices and the disrupted energy supply due to the Russia-Ukraine conflict. France announced plans to build six new nuclear reactors and to consider building a further eight. The first new one can be launched by 2035. The United Kingdom intends to get 25% of its electricity from nuclear power by 2050. Even though the conflict does not directly affect the supply and trade of Uranium, it has indirect effects through industrial chain transmission. Since the conflict, nuclear power has been considered again in the EU, and it increase the price of Uranium by 40%, at the top for 11 years. If the price continues to increase in the future, the global Uranium trade will be affected to some extent.

Reviewer 2 Report

Reviewer Comments on sustainability-1821128:

This paper examines the trading relationships in the natural and enriched uranium market using network analysis tools. An illustration of the changes over time is also provided. The main claim of the paper in terms of its novelty is the lack of a similar analysis of the uranium market. 

On the academic side, it is not well-justified why a network analysis of the flows across countries is needed or what additional insights it provides. Of course, it is possible to generate all the network density, sparseness, etc, values, but why are they important? The bilateral trade data across countries and the changes in their composition over time are all available. We do not see an explanatory "model" of uranium trade in the paper, but rather another version of a descriptive presentation. As such, the paper does not contribute to a better understanding of this market. Also, there is little discussion of the price side. The paper claims to look at both the demand and the supply side: then, where are the prices? A "model" that can explain the price formation and the changes in the structure of the market using the supply and demand side determinants would be more insightful. 

On the organizational side, the paper needs a good amount of language editing. The Figures and Maps are also not well-legible.

Author Response

This paper examines the trading relationships in the natural and enriched uranium market using network analysis tools. An illustration of the changes over time is also provided. The main claim of the paper in terms of its novelty is the lack of a similar analysis of the uranium market.

On the academic side, it is not well-justified why a network analysis of the flows across countries is needed or what additional insights it provides. Of course, it is possible to generate all the network density, sparseness, etc, values, but why are they important? The bilateral trade data across countries and the changes in their composition over time are all available. We do not see an explanatory "model" of uranium trade in the paper, but rather another version of a descriptive presentation. As such, the paper does not contribute to a better understanding of this market. Also, there is little discussion of the price side. The paper claims to look at both the demand and the supply side: then, where are the prices? A "model" that can explain the price formation and the changes in the structure of the market using the supply and demand side determinants would be more insightful. On the organizational side, the paper needs a good amount of language editing. The Figures and Maps are also not well-legible.

This paper mainly explores the characteristics of the Uranium trade pattern evolution. As there are few studies on the Uranium trade, it is of great value to investigate it. We have referred to some academic research on the pattern evolution of resource trade.

(1) Chunhui Wang , Weiqiong Zhong, Anjian Wang, Xiaoqi Sun, Tianjiao Li, Xingxing Wang. (2021). Mapping the evolution of international antimony ores trade pattern based on complex network. Resources Policy, 74, 102421.

(2) Meng Liu, Huajiao Li, Jinsheng Zhou , Sida Feng, Yanli Wang, Xingxing Wang. (2022). Analysis of material flow among multiple phases of cobalt industrial chain based on a complex network. Resources Policy, 77, 102691.

With the annual data, this paper focuses on the analysis of the influencing factors of Uranium supply and demand, and the price is just one of the most important factors. Therefore, research on prices is discussed as a factor. For example, “Affected by the global financial crisis in 2008, the price of uranium fell off a cliff, which led to a decrease in the modularity of the Natural Uranium trade network, and then maintained at around 0.4, indicating that the globalization has increased.”. However, the relationship between supply and demand of trade and price is not one of the main research questions. Through building a complex network model, this paper analyzed the characteristics of natural uranium and Enriched Uranium trade network from three levels - global, community, and key countries, and compared the trends of upstream and downstream productions in the industrial chain. With network density, sparseness, etc, values, the complex network method can help us illustrate some deeper characteristics of trade. This reviewer’s questions are valuable, and we would explore the changes in prices and their influences on the characteristics of the global uranium trade in the future.

Reviewer 3 Report

Referee Report on “Study on the characteristics and evolution trend of global uranium resource trade from the perspective of complex network”_ sustainability-1821128-peer-review-v1

 

This paper constructed the upstream Natural Uranium trade complex network (upstream) and the Enriched Uranium trade complex network (downstream) to analyze the characteristics and evolution trend of global Uranium resources trade networks (GURTN) from the global, community, and national levels based on the perspective of the industry chain. The trade of Enriched Uranium is mainly concentrated between developed countries such as European and North American countries. Natural Uranium is raw material, in general, almost every trade community has relatively fixed trading partners. This paper analyzes the changing trends of closeness centrality, between ness centrality, and eigencentrality of the major net importers and net exporters in Natural Uranium trade and Enriched Uranium trade respectively.

However, I have the following specific concerns.

 

Major Concerns and Comments:

1. The value and proportion of uranium trade volume (import and export) in major countries should be provided appropriately.

 

2. In Figure 1, the trade movements of Spain and the United Kingdom are very large, and the author should explain them.

 

3. The authors claim that the trade in natural uranium is regional and the trade in enriched uranium is global. It is suggested that the author can provide information on the concentration of importing and exporting countries in the uranium trade and the mileage of the trade as evidence.

 

4. The authors use year data, whether or not to ignore the storability of uranium. It is recommended to use moving averages (3 years or 5 years) to avoid large fluctuations in various indicators.

 

5. In page 15, the authors point out that "As the world's major Natural Uranium exporters, Kazakhstan, Australia, and Namibia have low betweenness centrality values and have little control over the Natural Uranium trade. Although China has become the world's second-largest consumer of Uranium resources and the largest importer of Natural Uranium, it does not participate in the global natural uranium trade at a deeper level due to its relatively concentrated import sources. It results in its lack of control ability in the natural uranium trade network (Fig.8(C))." The author uses performance indicators (such as betweenness centrality) to analyze the current status of uranium trade, so that other indicators (such as concentration ratio) can be used to explain the factors that affect performance indicators. I suggest that relevant explanations must be supported and demonstrated by data.

 

6. In conclusion, the authors point out that “Trading countries should take positive measures to deal with the impact on the market with the expiration of the USA-Russia Enriched Uranium trade agreement. In particular, Natural Uranium producers can increase supply appropriately to stabilize the market.” I don't know if the related effects are discussed in the text.

 

Evaluation:

For the above reasons, I believe that the current situation in this article is not suitable for publication in this journal. I encourage authors to make submissions after making appropriate revisions.

Comments for author File: Comments.pdf

Author Response

Author's Reply to the Review Report (Reviewer 3)

Referee Report on "Study on the characteristics and evolution trend of global uranium resource trade from the perspective of complex network"_ sustainability-1821128-peer-review-v1

 

This paper constructed the upstream Natural Uranium trade complex network (upstream) and the Enriched Uranium trade complex network (downstream) to analyze the characteristics and evolution trend of global Uranium resources trade networks (GURTN) from the global, community, and national levels based on the perspective of the industry chain. The trade of Enriched Uranium is mainly concentrated between developed countries such as European and North American countries. Natural Uranium is raw material, in general, almost every trade community has relatively fixed trading partners. This paper analyzes the changing trends of closeness centrality, between ness centrality, and eigencentrality of the major net importers and net exporters in Natural Uranium trade and Enriched Uranium trade respectively.

 

However, I have the following specific concerns.

 

Major Concerns and Comments:

 

1. The value and proportion of uranium trade volume (import and export) in major countries should be provided appropriately.

 

The worlds largest importers of Natural Uranium in 2019: China-36% of the world imports ($ 1297 million), Canada-21% ($745 million). At the same time, the country with the highest export value of Natural Uranium was Kazakhstan, accounting for 43% of the global exports ($1531 million). Canada was the worlds second-largest exporter of Natural Uranium, with 19% ($ 681 million). In 2019, the United States imported most of the Enriched Uranium, with 34% ($ 1716 million), which is followed by Korea with 14% ($ 707 million). The top two exporters of Enriched Uranium were Russia and Netherlands, at 1723 and 823 million U.S. dollars. These accounted for 34 and 16 percent shares of Enriched Uranium exports worldwide.

The value and proportion of uranium trade volume of major countries in 2019

 

2. In Figure 1, the trade movements of Spain and the United Kingdom are very large, and the author should explain them.

Lack of ability to convert and concentrate uranium, Spain solely relies on import for enriched uranium. Affected by the global financial crisis, the price of uranium resources fell. From 2008 to 2013, Spain mainly imported a large number of enriched uranium resources from the United Kingdom for storage, which caused great fluctuations in global trade volume.

 

3. The authors claim that the trade in natural uranium is regional and the trade in enriched uranium is global. It is suggested that the author can provide information on the concentration of importing and exporting countries in the uranium trade and the mileage of the trade as evidence.

The "regional" and "global" referred to in this paper are calculated through the modularity formula of complex networks and are relative. Taking 2019 as an example, the top five countries in Natural Uranium import and export have a concentration of over 90%, while Enriched Uranium is 80% (Tab.1 and 2).

Fig.1 Global Natural Uranium import and export volume and proportion in 2019

Ranking	Countries	Imports(t)	Proportion	Ranking	Countries	Exports(t)	Proportion
1	China	12817	24.31%	1	Kazakhstan	20749	39.35%
2	Canada	11772	22.33%	2	Canada	13922	26.40%
3	Russia	10801	20.48%	3	Australia	6063	11.50%
4	USA	6966	13.21%	4	Namibia	4611	8.74%
5	Germany	5871	11.13%	5	USA	1666	3.16%
6	France	2395	4.54%	6	France	1584	3.00%
7	Netherlands	1348	2.56%	7	Ukraine	1507	2.86%
8	Rep. of Korea	250	0.47%	8	Uzbekistan	1040	1.97%
9	Malaysia	163	0.31%	9	Niger	867	1.64%
10	Romania	155	0.29%	10	Czechia	217	0.41%
	Concentration of  top 5		91.47%		Concentration of top 5		89.16%
	Concentration of top 10		99.64%		Concentration of  top 10		99.05%

 

Fig.2 Global Enriched Uranium import and export volume and proportion in 2019

Ranking	Countries	Imports(t)	Proportion	Ranking	Countries	Exports(t)	Proportion
1	USA	2221	38.06%	1	Russian Federation	1827	31.30%
2	Sweden	743	12.73%	2	Netherlands	1212	20.77%
3	United Kingdom	627	10.74%	3	Germany	778	13.32%
4	China	601	10.31%	4	United Kingdom	547	9.37%
5	Rep. of Korea	497	8.52%	5	France	502	8.59%
6	France	420	7.19%	6	Spain	327	5.60%
7	Germany	225	3.85%	7	Areas, nes	135	2.31%
8	Spain	195	3.34%	8	Kazakhstan	117	2.00%
9	Kazakhstan	132	2.26%	9	Canada	111	1.90%
10	Belgium	128	2.20%	10	Australia	73	1.25%
	Concentration of top 5		80.35%		Concentration of top 5		83.35%
	Concentration of top 10		99.19%		Concentration of top 10		96.42%

 

Taking China and the United States as examples, China and the United States mainly rely on neighboring countries for their Natural Uranium imports. Chinas Natural Uranium imports mainly come from Uzbekistan, while the United States mainly comes from Canada (Fig.1 and 2).

 

Fig.1 China's Natural Uranium imports and proportion

 

Fig.2 Americas Natural Uranium imports and proportion

The U.S.A Enriched Uranium trade is more globalized, with Japan, South Korea and Kazakhstan in addition to European countries (Fig.3).

 

Fig.3 Imports and exports of enriched uranium in the United States, 2000-2019.

 

 

4. The authors use year data, whether or not to ignore the storability of uranium. It is recommended to use moving averages (3 years or 5 years) to avoid large fluctuations in various indicators.

The author believes that due to the short study period (2000-2019), if moving averages (3 or 5 years) are used, key information may be overlooked, such as the financial crisis in 2008 and the  Fukushima nuclear accident in 2011 on the trade pattern Impact.

 

5. In page 15, the authors point out that "As the world's major Natural Uranium exporters, Kazakhstan, Australia, and Namibia have low betweenness centrality values and have little control over the Natural Uranium trade. Although China has become the world's second-largest consumer of Uranium resources and the largest importer of Natural Uranium, it does not participate in the global natural uranium trade at a deeper level due to its relatively concentrated import sources. It results in its lack of control ability in the natural uranium trade network (Fig.8(C))." The author uses performance indicators (such as betweenness centrality) to analyze the current status of uranium trade, so that other indicators (such as concentration ratio) can be used to explain the factors that affect performance indicators. I suggest that relevant explanations must be supported and demonstrated by data.

   Added corresponding analysis to the article: Although China has become the world's second-largest consumer of Uranium resources(In 2019, China’s uranium resource consumption was 9834t, second only to the United States’ 19746t.) and the largest importer of Natural Uranium(Over 60% of imports come from Kazakhstan.)

 

6. In conclusion, the authors point out that “Trading countries should take positive measures to deal with the impact on the market with the expiration of the USA-Russia Enriched Uranium trade agreement. In particular, Natural Uranium producers can increase supply appropriately to stabilize the market.” I don't know if the related effects are discussed in the text.

 

Added corresponding analysis to the article：If the USA-Russia Enriched Uranium trade agreement does not not renewed after its expiration. This means that both countries need to purchase corresponding uranium resources from the market to make up for the vacancy, which will lead to an increase in the price of uranium to a certain extent. If the two countries fail to purchase the corresponding uranium resources in the short term, the impact will be transmitted through the industrial chain.

At the same time, in order to end the dependency on Russian fossil fuels, many European countries proposed to invest in nuclear power. Belgium has decided to postpone its nuclear phase-out scheduled for 2025 by 10 years, worried about the soaring energy prices and the disrupted energy supply due to the Russia-Ukraine conflict. France announced plans to build six new nuclear reactors and to consider building a further eight. The first new one can be launched by 2035. The United Kingdom intends to get 25% of its electricity from nuclear power by 2050. Even though the conflict does not directly affect the supply and trade of Uranium, it has indirect effects through industrial chain transmission. Since the conflict, nuclear power has been considered again in the EU, and it increase the price of Uranium by 40%, at the top for 11 years. If the price continues to increase in the future, the global Uranium trade will be affected to some extent.

Author Response File: Author Response.pdf

Reviewer 4 Report

This is a potentially interesting and useful piece of analysis that would benefit from some attention to detail.  I think the audience could be expanded if the authors will put a bit of time and effort into expanding the discussion of their framework.  In addition, the authors missed some opportunities to provide greater impact of their results.  I discuss these points below.

1. The likely audience for the current version of the paper would be scholars who work on network theory.  But experts on the uranium industry are unlikely to fall into that group; I think they are more likely to be comfortable applying economic principles to this industry.  In my opinion, the authors could do more to encourage such readers to spend the time and effort to read through this paper: for example, by explaining how learning a bit about networks would allow the reader to better understand some key features of the uranium industry.  To that end, I encourage the authors to consult the work of by Matthew Jackson; his recent book ``The Human Network" would be a fine place to start.
2. The authors document important differences between native and enriched uranium, but miss an opportunity to increase the paper's appeal by explaining why such differences arise.  My guess is these differences can be explained by key differences in the market structure for these two segments: while there are many sources of native uranium, suggesting that market has low concentration (no seller has much - if any - market power), enrichment is highly capital intensive, and so that market segment tends to be far more concentrated.  Perhaps that additional concentration makes it harder to locate a trading partner, thereby making enrichment a more stable network?  The authors may have other explanation; the point here is that they need to say something about why these two segments are so different.
3. The paper would benefit from a careful proof-reading.  I found a handful of typos and punctuation errors that need to be corrected.

Author Response

This is a potentially interesting and useful piece of analysis that would benefit from some attention to detail. I think the audience could be expanded if the authors will put a bit of time and effort into expanding the discussion of their framework. In addition, the authors missed some opportunities to provide greater impact of their results. I discuss these points below.

 

1. The likely audience for the current version of the paper would be scholars who work on network theory. But experts on the uranium industry are unlikely to fall into that group; I think they are more likely to be comfortable applying economic principles to this industry.In my opinion, the authors could do more to encourage such readers to spend the time and effort to read through this paper: for example, by explaining how learning a bit about networks would allow the reader to better understand some key features of the uranium industry.  To that end, I encourage the authors to consult the work of by Matthew Jackson; his recent book ``The Human Network" would be a fine place to start.

According to the recommendations from the Reviewer, the authors read “The Human Network”, and would try to use it in the future.

2. The authors document important differences between native and enriched uranium, but miss an opportunity to increase the paper's appeal by explaining why such differences arise.  My guess is these differences can be explained by key differences in the market structure for these two segments: while there are many sources of native uranium, suggesting that market has low concentration (no seller has much - if any - market power), enrichment is highly capital intensive, and so that market segment tends to be far more concentrated.  Perhaps that additional concentration makes it harder to locate a trading partner, thereby making enrichment a more stable network? The authors may have other explanation; the point here is that they need to say something about why these two segments are so different.

The trade concentration of the top ten countries for import and export of Natural Uranium and Enriched Uranium is basically the same, with only a slight difference in the concentration of the top five. Therefore, the degree of concentration cannot well explain the difference between the two resource markets(Fig.1, 2). The author also proposed in the article “The production of Enriched Uranium generally adopts the way of entrusted processing. The demand country provides raw materials, and the producing country is responsible for processing and then exporting to the demanding country.” However, the reviewer's suggestion for analyzing the characteristics of the enriched uranium trade gave the author inspiration, which was revised in the text.

 

Fig.1 Global Natural Uranium import and export volume and proportion in 2019

Ranking	Countries	Imports(t)	Proportion	Ranking	Countries	Exports(t)	Proportion
1	China	12817	24.31%	1	Kazakhstan	20749	39.35%
2	Canada	11772	22.33%	2	Canada	13922	26.40%
3	Russia	10801	20.48%	3	Australia	6063	11.50%
4	USA	6966	13.21%	4	Namibia	4611	8.74%
5	Germany	5871	11.13%	5	USA	1666	3.16%
6	France	2395	4.54%	6	France	1584	3.00%
7	Netherlands	1348	2.56%	7	Ukraine	1507	2.86%
8	Rep. of Korea	250	0.47%	8	Uzbekistan	1040	1.97%
9	Malaysia	163	0.31%	9	Niger	867	1.64%
10	Romania	155	0.29%	10	Czechia	217	0.41%
	Concentration of  top 5		91.47%		Concentration of top 5		89.16%
	Concentration of top 10		99.64%		Concentration of  top 10		99.05%

 

Fig.2 Global Enriched Uranium import and export volume and proportion in 2019

Ranking	Countries	Imports(t)	Proportion	Ranking	Countries	Exports(t)	Proportion
1	USA	2221	38.06%	1	Russian Federation	1827	31.30%
2	Sweden	743	12.73%	2	Netherlands	1212	20.77%
3	United Kingdom	627	10.74%	3	Germany	778	13.32%
4	China	601	10.31%	4	United Kingdom	547	9.37%
5	Rep. of Korea	497	8.52%	5	France	502	8.59%
6	France	420	7.19%	6	Spain	327	5.60%
7	Germany	225	3.85%	7	Areas, nes	135	2.31%
8	Spain	195	3.34%	8	Kazakhstan	117	2.00%
9	Kazakhstan	132	2.26%	9	Canada	111	1.90%
10	Belgium	128	2.20%	10	Australia	73	1.25%
	Concentration of top 5		80.35%		Concentration of top 5		83.35%
	Concentration of top 10		99.19%		Concentration of top 10		96.42%

 

 

 

3. The paper would benefit from a careful proof-reading. I found a handful of typos and punctuation errors that need to be corrected.

The author has corrected spelling and punctuation errors in the article.

Round 2

Reviewer 2 Report

Dear Authors: Thanks for the revisions and the clarifications. It is not clear what novel research questions this paper addresses and what hypotheses it develops and tests. It is only descriptive analysis by means of network models. What should market players or policymakers make out of the network analysis results? As I stated in my earlier report, bilateral trade flows are already available. What is needed is a well-developed structural model that provides new insights or that challenges the patterns from descriptive statistics. Otherwise, it is still in the domain of a market analysis report that employs more complicated technical tools rather than an academic contribution to the field. 

Author Response

Dear Reviewers:

Thank you so much for your review comments.

On the basis of complex network analysis, we added the correlation analysis between Uranium price and GURTN’s indicators.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Dear Authors:

Thank you for your efforts to extend the analysis and include a number of bivariate correlation coefficients. Nevertheless, the bivariate correlation between X and Y in the absence of any third variable Z that may influence both X and Y can be very misleading. Hence, the correlation coefficient alone does not provide much information. In addition, as it is well-known, correction is not causality. If you could show causal evidence in your paper, it would be more promising.

Author Response

In order to analyze the influence of Uranium price on major TURTN’s indicators further, this paper tests the Granger Causality between the price of Uranium and major Natural Uranium trade network indicators, and the price of Uranium and major Enriched Uranium trade network indicators respectively. In the natural uranium trade network, Price and M pass the 5% significance test, and price and AD pass the 10% significance test, indicating that price changes will affect the connectivity and globalization of trade networks.In the enriched uranium trade network, Price and AD pass the 10% significance test, indicating that price changes will affect trade network connectivity (Tab.3).

 

Tab.3 Granger causality test results between Uranium price and major TURTN’s indicators.

284410		F	P	284420		F	P
AD	Price	0.177	0.84	AD	Price	0.408	0.673
Price	AD	3.4	0.065*	Price	AD	3.328	0.068*
ND	Price	0.483	0.627	ND	Price	1.358	0.291
Price	ND	0.025	0.975	Price	ND	1.493	0.261
M	Price	1.712	0.219	M	Price	1.639	0.232
Price	M	4.675	0.030**	Price	M	0.71	0.51
ACC	Price	0.821	0.462	ACC	Price	2.692	0.105
Price	ACC	0.298	0.747	Price	ACC	0.074	0.929
APL	Price	0.2	0.821	APL	Price	0.113	0.894
Price	APL	0.514	0.61	Price	APL	0.886	0.436
***, **, and * represent the significance levels of 1%, 5%, and 10%

 

Author Response File: Author Response.docx