Discussion Paper No.296
Panel data analysis of the inbound tourism demand
and tourism policy in Laos
Tomoya MORI
Faculty of Education
Yamaguchi University

December 2017

INSTITUTE OF ECONOMIC RESEARCH
Chuo University
Tokyo, Japan

Panel data analysis of the inbound tourism demand and tourism policyin Laos*
Tomoya MORI
Faculty of Education, Yamaguchi University, Japan
1677-1,Yoshida, Yamaguchi, 753-8513
Tel: +81-83-933-5328
E-mail: moritomo@yamaguchi-u.ac.jp

The purpose of this research is to investigate the determinants of the inbounddemand in Laos by using a gravity model with panel data from 2000–2014. Ourmodel includes not only income and price factors considered in previous studies
but also the factors pertaining to three tourism policies: (1) visa easing, (2)development of economic corridors within GMS, and (3) the registration of
UNESCO World Heritage Sites in Laos in 2001. The results indicate that the
number of tourists from Cambodia, Malaysia, Singapore, Thailand, Vietnam, andMyanmar can increase after implementing visa permissions; however, we cannot
find accurate numbers for the Philippines, Brunei, and Indonesia. In addition, theestablishment of the East-West and South-North Economic Corridors encourages
the inbound demand from not only Thailand but also Vietnam and China.
Eventually, this research suggests some initiatives required for long-term growthin the tourism sector based on the results, considering the “tourist area life cycle”
hypothesis by Butler (1980).
Keywords: panel data; tourism policy; inbound demand; Laos
JEL classification codes: C33, D12, Z32, Z38

Introduction
Lao People’s Democratic Republic (referred to as Laos hereafter) is a landlocked
country surrounded by Myanmar, Thailand, Vietnam, Cambodia, and China in South
East Asia. The tourism sector is one of the most important industries and the source of
foreign currency in Laos (Yamauchi & Lee, 1999). According to World Travel &Tourism Council (2017), the tourism market constituted about 14.2% of the GDP and12.4% of the total labor in 2016. The number of inbound tourists in Laos has been
increasing since the government started admitting foreigners into the country in October
1989 (Harrison & Schipani, 2009). According to the Tourism Development Department(2017), the number of inbound tourists was over four million and the revenue was 724
1

million USD in 2016 (refer to Figure 1).
In 1990, Laos’s government made a master plan of their tourism strategy withsupport from the World Tourism Organization of the United Nations for encouraging
the tourism industry to grow continuously. In addition, the tourism industry in countries
along the Mekong River is expected to be developed by the economic cooperation
program, “Greater Mekong Sub-region: GMS,” in collaboration with the AsianDevelopment Bank. The GMS countries include Myanmar, Laos, Thailand, Vietnam,
Cambodia, and the Yunnan province and Jiangxi Zhuang Autonomous Region in China.
The GMS program has implemented many projects such as the construction of three
economic corridors (South-North, East-West, and South) to promote trade andinvestment among the intra-regions. Due to their efforts, Laos was ranked first among
the countries people want to visit in 2008 by New York Times in 2007 (Lee, 2007,
December 9). Moreover, in 2013, Laos was awarded “World’s Best Tourist
Destination” for 2013 by European Council on Tourism and Trade (ECTT) (ASEAN
Secretariat News, 2013, May 22). ECTT honored the efforts to preserve natural andcultural heritages, including two UNESCO World Heritages; the “Town of Luang
Prabang” in the Luang Prabang province and “Vat Phou and Associated Ancient
Settlements within the Champasak Cultural Landscape” in the Champasak province(Valentin and Schilcher, 2017).
Figure 1: Number of inbound and the Revenue
5,000
4,500

700
600
500

4,000

Number

3,500

Revenue

3,000

400

2,500
2,000

300

1,500

200

1,000

100

Number（Thousand person）

Revenue （million USD）

800

500

0

0

2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990

Source: Author’s own construction based on the Tourism Development Department (2017).

However, Laos’s government targets the number of foreign visitors to reacharound six million in 2020 because of the decline in the number of tourists in 2016, andhopes that the number of inbound tourists will continuously increase (Souliyong,
February 11, 2017). Moreover, the government has established the year 2018 as the“Visit Laos Year,” and is attempting to promote the tourism industry toward 2018 andsustain the tourism growth in the future. However, the “tourist area life cycle”
hypothesis by Butler (1980) indicates that the rate of the tourism demand grows rapidly2

in the developing stage, and gradually decreases over time, eventually reachingstagnancy. The path of the growth rate after the stagnant stage has different possibilities:
rejuvenation or decline. Accordingly, it is important to clarify the factors that influence
inbound tourism in Laos, and suggest a strategy to maintain the sectoral growth,
considering the future of Laos as a tourism-based country. Thus, the aim of this paper isto understand the demand trends for inbound tourism and demonstrate empirically thefactors that influence demand.
Nonthapot and Lean (2013) and Phakdisoth and Kim (2007) are typical researchstudies that use the quantitative approach. Nonthapot and Lean (2013) focuses only on
the inbound demand from Thailand because Thailand’s tourists occupy the highest
market share among the inbound tourists in Laos, and they analyse it with the timeseries data. However, for developing a strategy about the tourism industry based on the
results, the implication of this research can apply only to the tourists from Thailand, andnot the total inbound demand in Laos. For this, we need to estimate the inbound demandwith panel data, and not time series data or cross-section data.
Phakdisoth and Kim (2007) specifies the inbound demand with a panel data
analysis spanning ten years, from 1994 to 2004. Phakdisoth and Kim (2007) estimatesthe inbound demand with not only the factor of origin countries but also that of thedestination country. Their estimation adopts the factor of demand (price and income) as
the variable for origin countries, and the factor of supply (length of road, telephone
mainline, and so on) as that of the destination country. However, the estimation of thedemand function with the variable of the supply side is considered biased because of theendogeneity. The system in the endogeneity has an identification problem (Greene,2002).
The gravity model is a typical methodology to analyze international tourism
with both factors of origin and destination countries without the bias as describedearlier. According to Morley, Rosselo and Santana-Gallego (2014), the gravity model
assumes that bilateral flows between two countries are directly proportional to thecountries’ economic masses and inversely proportional to the distance between them.
This study uses the gravity model with flows from various origin countries into a
specific destination country. Although such a model cannot identify common factors
and the impact to affect bilateral flows between two countries (Morley et al., 2014), thepurpose of this study is to grasp the inbound demand in Laos so that we could estimate
flows from various origin countries into Laos.
Furthermore, previous studies do not consider the effect of the tourism policy on
demand. The tourism policy is expected to also encourage inbound tourism to increase.
Focusing on the tourism policy, we clarify that the travel policy will have a significant
effect on increasing inbound tourism as well as income and relative price. We willconsider this aspect in the next section.
3

From the abovementioned information, we try to quantitatively analyze theinbound demand in Laos with the gravity model, taking the tourism policy into theestimation. The remainder of the paper is organized as follows. Section 2 explains thetourism policy in Laos to influence sufficiently the inbound demand in the country.
Section 3 presents the research method and the variables used. Section 4 shows theresults of the estimation. Section 5 discusses the feature of the inbound demand in Laosand suggests some implementations by the “tourist area life cycle” hypothesis (Butler,1980). Section 6 concludes and presents potential avenues for further research.
Tourism policy in Laos
Laos’s government develops various strategies and implements many kinds of tourism
policies. Of them, we focus on three implementations that largely influence the rise of
the inbound demand: (1) visa easing, (2) development of economic corridors within
GMS, and (3) the registration of UNESCO World Heritage Sites in Laos in 2001. Table
1 presents the history of the three implementations in Laos.
Laos’s government has released the visa restriction for foreign countries. The
visa permission has the different purposes of passports (diplomatic, service, andordinary). This study considers visa permission for ordinary passports. In 2004, Laos’s
government eased the visa restrictions for Thailand, Vietnam, Cambodia, Malaysia, andSingapore only for a stay of thirty days. After this, visa easing was implemented forother countries as well, including Philippines and Brunei in 2005, Japan and Russia in
2007, the Republic of Korea in 2008, Myanmar and Switzerland in 2009, and Indonesia
in 2011. It is thus expected that the inbound demand of these 11 countries increased
after their respective years of visa easing.
Table 1: History of the Tourism Policy in LaosYear

Contents

1994

First Friendship bridge was built and permitted and released the regulation which Lao people move within Laos.

2001

The registration of “Vat Phou and Associated Ancient Settlements within the Champasak Cultural Landscape” in Champasak province
as UNESCO World Heritage.

2004

Visa easing for Cambodia, Malaysia, Singapore, Thailand and Vietnam as long as staying for thirty days.

2005

Visa easing for Philippine and Brunei as long as staying for thirty days.

2007

Second Friendship bridge was permitted.
Visa easing for Japan and Russia as long as staying for thirty days.

2008

Visa easing for Rep. of Korea as long as staying for fifty days.

2009

Visa easing for Myanmar and Switzerland as long as staying for thirty days.

4

2011

Third Friendship bridge was built and permitted.
Visa easing for Indonesia as long as staying for thirty days.

2013

Fourth Friendship bridge was built and permitted.

Source: Author’s own construction based on Fujimura (2016), Japan External Trade
Organization (2015) and the Lao Airlines website.

Some travelers from the neighboring countries of Thailand, Vietnam, Cambodia,
Myanmar, and China enter through the land route (refer to Table 2). Specifically, many
travelers enter Laos through the land route from Thailand, which has the most share of
inbound tourism in Laos. As of 2016, Laos had ten entry points across Thailand. Of
them, four friendship bridges were present between Laos and Thailand until 2016. The
first friendship bridge was built to connect Vientiane and the Nong Khai province inThailand in 1994. The second bridge was built to connect the Savannakhet province in
Laos and the Mokdahan province in Thailand in December 2016, and passage by
vehicle was officially permitted in January 2007. The second friendship bridge isincluded as a part of the East-West Economic Corridor to link Da Nang city in Vietnam
to Mon state in Myanmar. The third friendship bridge to connect the Khammouane
province in Laos to Nakhon Phanom province in Thailand was opened for traffic in
2011. The construction of this fourth bridge was completed in 2013, and connects
Bokeo province in Laos to Chaing Rai province in Thailand, and is a part of the SouthNorth Economic Corridor connecting Kunming city in Yunnan province, China to
Bangkok city in Thailand, and the Asian Highway.
Table 2: The Whole Tourist and Tourists on Land Route in 2016
Countries(A) Total Tourists (Ratio of the whole travelers)

Tourists on land route (Ratio of (A))

Thailand

2,009,605 (47%)

949,536 (47%)

Vietnam

998,400 (24%)

69,441 (7%)

China

545,493 (13%)

162,874 (30%)

Cambodia

16,536 (0.4%)

2,300 (13%)

Source: Author’s construction based on Tourism Development Department (2017).

The construction of these friendship bridges could increase the number oftourists from Thailand. Moreover, because two economic corridors have been expanded
due to the construction of the second and fourth bridges, the human flow among
Vietnam, Laos, and Thailand, and among China, Laos, and Thailand could increase.
Some empirical research studies attempt to analyze the influence of thedevelopment of an economic corridor on the intra-regional economy (Brunner, 2013;
Fujimura, 2016; Susan & Anna, 2009). Fujimura (2016) quantitatively evaluates the5impact on the growth of GDP per capita and the trade value in the electric and transportmachinery based on econometric methodology, panel data analysis, and the gravity
model. Nonthapot (2016) studies the relationship between tourism and economic growth
in intra-GMS countries, but not in each country. Nonthapot (2016) also shows that the
tourism expenditure for passenger transport mediates the path from economic growth tothe tourism’s contribution to the GMS, and suggests that all GMS countries should
invest resources to develop the transport sector. However, the previous studies do notconsider the introduction of tourism policy influences on the tourism sector. Thus, thisis a significant contribution of our investigation.
Figure: 2 Friendship Bridges between Laos and Thailand
North-South Economic Corridor

FourthFriendship Bridge

First Friendship Bridge
Third Friendship Bridge

Second Friendship Bridge

East-West Economic Corridor

Sources: Author’s construction based on the blank map data obtained from d-map.com (http://dmaps.com/index.php?lang=en).

As mentioned before, Laos has two UNESCO World Heritage Sites: the “Townof Luang Prabang” in the Luang Prabang province and “Vat Phou and AssociatedAncient Settlements within the Champasak Cultural Landscape” in the Champasak
province. The “Town of Luang Prabang” was registered in 1995 and “Vat Phou andAssociated Ancient Settlements within the Champasak Cultural Landscape” in 2000.
6

Since information is not available on the number of tourists from each foreign country
before 1995; therefore, this research attempts to examine the effect of the UNESCO
registration in 2000 because we cannot have the data.
Based on the preceding, to consider comprehensively the inbound demand in
Laos, this study adopts three tourism policies as the independent variable, as well as theincome factor and the relative prices in origin countries.
Research method and data
This study makes two estimations with the panel data from 2000 to 2007 and from 2007
to 2014: thirty two countries and eight years1. This is because we would like to reducetime trends and avoid problems such as unit root or cointegration. we need to address
their issues in the case of the estimation used for long term and establish a complex
model.
Some studies criticize that the gravity model applied to international tourism
does not have a theoretical foundation (Morley et al., 2014). Morley et al. (2014)
modifies the gravity model for international tourism in the context of a consumer’sutility theory in economics. The model based on a consumer’s utility theory focuses on
the income and price factors. This research estimates an expression of a linear
logarithmic model (1) based on the prior section.
ln 𝐼𝐷𝑖𝑡 = 𝛽0 + 𝛽1 ln 𝑌𝑖𝑡 + 𝛽2 ln 𝑌𝑗𝑡 + 𝛽3 ln 𝑅𝑃𝑖𝑗𝑡 + 𝛽4 ln 𝑃𝑜𝑝𝑖𝑡 + 𝛽5 ln 𝑃𝑜𝑝𝑗𝑡 + 𝛽6 ln 𝐷𝑖𝑠𝑡𝑖+𝛽7 (𝑉𝑖𝑠𝑎𝑖 × 𝐴𝐹𝑇𝐸𝑅𝑡 ) + 𝛽8 (𝐺𝑀𝑆 𝑐𝑜𝑢𝑛𝑡𝑟𝑦𝑖 × 𝐴𝐹𝑇𝐸𝑅𝑡 ) + 𝛽9 𝑉𝑖𝑠𝑎𝑖 + 𝛽10 𝐴𝐹𝑇𝐸𝑅𝑡+𝛽11 𝐺𝑀𝑆 𝑐𝑜𝑢𝑡𝑟𝑦𝑖 + 𝛽12 𝑌𝑟𝑡 + 𝜇𝑖 + 𝜀𝑖𝑡 (1)The dependent variable 𝐼𝐷𝑖𝑡 represents the inbound demand in Laos. In general,the gravity model adopts the number of tourists and their expenditure as the proxy of
𝐼𝐷𝑖𝑡 . However, since the panel data regarding the expenditure of tourists is notavailable, we use the number of tourists as the proxy of 𝐼𝐷𝑖𝑡 .
Regarding the independent variable, we adopt real GDP per capita in origin
countries 𝑌𝑖𝑡 as the proxy of the income factor of tourists in the origin country, and real
GDP per capita in the destination country 𝑌𝑗𝑡 as the proxy of the destination quality
indicator according to Morley et al. (2014). Both factors are considered to positively
influence the inbound demand. Besides, 𝐷𝑖𝑠𝑡𝑖 is the distance between two countries. It
is regarded as a kind of travel cost. In addition, the relative price between the origin andthe destination is an important factor for determining the demand for inbound tourism.
𝑅𝑃𝑖𝑗𝑡 is the relative price, representing the expenditure in the destination country
relative to that in the origin country. The relative price is represented as follows:
7

(

𝐶𝑃𝐼𝑖
⁄𝐸𝑋 )
𝑖

(

⁄𝐸𝑋 )
𝑗

𝑅𝑃𝑖𝑗𝑡 = 𝐶𝑃𝐼𝑗

𝐶𝑃𝐼𝑖
𝐸𝑋
=(
⁄𝐶𝑃𝐼 ) / ( 𝑖⁄𝐸𝑋 )
𝑗

(2)

𝑗

𝐶𝑃𝐼𝑖 and 𝐶𝑃𝐼𝑗 represent the consumer price indexes in the origin country 𝑖, andthe destination country (Laos), respectively. 𝐸𝑋𝑖 and 𝐸𝑋𝑗 represent the exchange ratesof the domestic currencies in 𝑖 and 𝑗 in terms of the US dollar, respectively. The
relative price has a negative influence on inbound tourism demand.
The other variables are population and specific events such as festivals,
disasters, and political disturbances. 𝑃𝑜𝑝𝑖𝑡 and 𝑃𝑜𝑝𝑗𝑡 represent the populations in i andj, respectively. Culiuc (2014) concludes that the populations in the origin anddestination countries have a negative effect on inbound tourism demand. Culiuc (2014)
explains that this is because residents in richer countries travel more to foreign countries
and tourists prefer richer countries given that countries with a lower population growth
are relatively richer compared with those experiencing a higher growth.
However, some research studies find that the population in origin countries
encourages an increase in the number of international tourists (e.g., Hanafiash & Harun,
2010; Lorde, Li & Airey , 2015; Massidda & Etzo, 2012). The research of Lorde et al.
(2015) regarding the inbound demand for Caribbean countries indicates that the
population growth in the origin countries increases the inbound tourists, and that the
number of foreign tourists declines more as the population in the destination country
increases. Lorde et al. (2015) suggests that countries with a small population, such as
the Caribbean countries, need to allocate more resources in sectors other than tourism
because the population of the destination increases. Therefore, prior studies do not haveany common consensus about the estimators of the population.
𝑉𝑖𝑠𝑎𝑖 is the dummy variable, which is 1 if visa restrictions are eased and 0
otherwise. 𝐴𝐹𝑇𝐸𝑅𝑡 is the time dummy variable, which is 1 after visa restrictions are
eased and 0 before they are eased. The cross term 𝑉𝑖𝑠𝑎𝑖 × 𝐴𝐹𝑇𝐸𝑅𝑡 is the difference
between a country that eases visa restrictions and other countries.
𝐺𝑀𝑆 𝑐𝑜𝑢𝑛𝑡𝑟𝑦𝑖 is also a dummy variable, which is 1 if country 𝑖 is Thailand,
Vietnam, or China, and 0 otherwise. The cross term 𝐺𝑀𝑆 𝑐𝑜𝑢𝑛𝑡𝑟𝑦𝑖 × 𝐴𝐹𝑇𝐸𝑅𝑡 implies
the effect of the friendship bridge on the inbound demand since the bridge is completed.
Although the second friendship bridge was built in December 2006, we consider itfunctional since 2007, being the year when Laos first permitted traffic on it.
𝑌𝑟𝑡 is the time dummy variable. This study considers the UNESCO World
Heritage time dummy in 2001 as the tourism policy and the SARS time dummy in 2003.
𝜇𝑖 refers to a specific fixed country and the time-invariant effect. 𝜀𝑖𝑡 is the error term.
Table 3: The Basic Descriptive Statistics
8

Size

Min.

Max.

Med.

Ave.

S.E.

2000-2007

256

4.934

13.764

8.333

8.643

0.096

2007-2014

256

5.283

14.538

8.955

9.298

0.108

2000-2007

256

2.740

2.747

2.744

2.744

0.000

2007-2014

256

6.584

11.42510.552

9.981

0.078

2000-2007

256-10.028

6.861-8.796-7.1090.197

2007-2014

256

6.861

7.280

7.068

7.069

0.009

2000-2007

256

4.742

8.098

7.531

7.043

0.057

2007-2014

256

4.742

8.098

7.531

7.043

0.057

2000-2007248-10.0280.746-8.796-7.1090.197

2007-2014253

15.59715.716-8.660-6.8780.193

2000-2007

25612.70920.99917.17217.1600.107

2007-2014

256

12.83321.03417.26117.2230.107

2000-2007

256

15.491

15.59715.542

15.543

0.002

2007-2014

256

15.59715.71615.65815.657

0.002

𝒀𝒓𝟎𝟏 , 𝒀𝒓𝟎𝟑

2000-2007

256

0.000

1.000

0.000

0.125

0.021

𝑨𝒇𝒕𝒆𝒓𝟎𝟒

2000-2007

256

0.000

1.000

0.500

0.500

0.031

𝑨𝒇𝒕𝒆𝒓𝟎𝟓

2000-2007

256

0.000

1.000

0.000

0.375

0.030

𝑨𝒇𝒕𝒆𝒓𝟎𝟕

2000-2007

256

0.000

1.000

0.000

0.125

0.021

𝑨𝒇𝒕𝒆𝒓𝟎𝟖

2007-2014

256

0.000

1.000

1.000

0.750

0.027

𝑨𝒇𝒕𝒆𝒓𝟎𝟗

2007-2014

256

0.000

1.000

1.000

0.750

0.027

𝑨𝒇𝒕𝒆𝒓𝟏𝟏

2007-2014

256

0.000

1.000

0.500

0.500

0.031

𝑨𝒇𝒕𝒆𝒓𝟏𝟑

2007-2014

256

0.000

1.000

0.000

0.250

0.027

𝑽𝒊𝒔𝒂𝟎𝟒

2000-2007

256

0.000

1.000

0.000

0.121

0.020

𝑽𝒊𝒔𝒂𝟎𝟓

2000-2007

256

0.000

1.000

0.000

0.063

0.015

𝑽𝒊𝒔𝒂𝟎𝟕

2000-2007

256

0.000

1.000

0.000

0.063

0.015

𝑽𝒊𝒔𝒂𝟎𝟖

2007-2014

256

0.000

1.000

0.000

0.031

0.011

𝑽𝒊𝒔𝒂𝟎𝟗2007-2014

256

0.000

1.000

0.000

0.031

0.011

𝑽𝒊𝒔𝒂𝟏𝟏

2007-2014

256

0.000

1.000

0.000

0.031

0.011

𝑻𝒉𝒂𝒊, 𝑽𝒊𝒆𝒕, 𝑪𝒉𝒊𝒏𝒂

2000-200
256

0.000

1.000

0.000

0.031

0.011

𝐥𝐧 𝑰𝑫𝒊𝒕𝐥𝐧 𝒀𝒊𝒕𝐥𝐧 𝒀𝒋𝒕(𝑳𝒂𝒐𝒔)

𝐥𝐧 𝑫𝒊𝒔𝒕𝒊 (𝒎𝒊𝒍𝒆)ln 𝑹𝑷𝒊𝒋𝒕

𝐥𝐧 𝑷𝒐𝒑𝒊𝒕𝐥𝐧 𝑷𝒐𝒑𝒋𝒕 (𝑳𝒂𝒐𝒔)

2007-2014

Table 4: Data Sources
Variable
𝐼𝐷𝑖𝑡

Data Sources
The Arrival numbers

2011-2016 Statistical Report on Tourism in Laos
1975-2005 Basic Statistic of the Socio-Economic Development in Laos𝑌𝑖𝑡 , 𝑌𝑗𝑡

Real GDP per capita

World Bank Indicator, World Bank

𝑅𝑃𝑖𝑗𝑡

CPI

World Bank Indicator, World Bank

Exchange rate

World Bank Indicator, World Bank

9

𝑃𝑜𝑝𝑖𝑡 , 𝑃𝑜𝑝𝑗𝑡

Population

World Bank Indicator, World Bank

Table 5: List of 32 Origin Countries
Brunei, Indonesia, Cambodia, Malaysia, Philippine, Singapore, Thailand, Vietnam, Australia, China, India, Japan, Republic of Korea, New Zealand,
Austria, Belgium, Denmark, Finland, France, German, Greece, Italy, Netherlands, Norway, Russia, Spain, Sweden, Switzerland, United Kingdom,
Canada, United States, Israel

Table 3 shows the basic descriptive statistics of each variable, Table 4 presents
the data sources, and Table 5 describes the 32 origin countries. This investigation does
not include Myanmar in the sample although the number of tourists from Myanmar is
expected to increase because the military regime ended in 2011 and a new friendshipbridge was built between Laos and Myanmar in 2015 (Ministry of Planning andInvestment of Laos, 2017, July 4). Nevertheless, the reason we exclude Myanmar fromthe sample is that the country changed from the multiple exchange rate to the controlled
floating exchange rate in 2012, making it difficult to calculate the value in expression(2).

Results of estimation
Table 6 demonstrates the result of each model. In the estimation with the panel data, wehave to determine the best among three models: fixed effect, random effect, and poolmodels. Hence, this investigation chooses the best model by the Breusch-Pagan test
(random effect model vs. pool model) and the Wu-Hausman test (random effect modelvs. fixed effect model). First, the Breusch-Pagan test indicates that the random effectmodel is more appropriate than the pool model. Second, we attempt Wu-Hausman test.
However, the result of the Wu-Hausman test shows that the probability is 1.00 because
the cross section test variance is invalid and the Wu-Hausman statistics are set to zero2.
Thus, this paper shows the result of both random effect (RE) model and fixed effect (FE)model. Additionally, this study also adopts first-order difference (FD) model whichremoves the time-invariant effects as well as fixed effect model though the sample sizeof the first difference model is smaller than the other models. As seen in the table 6, threemodels demonstrate mostly similar estimations although the result with the first-orderdifference (FD) model has some insignificant estimators than other models due to smaller
sample size.

10

Table 6: Estimates of Gravity Models
2000-2007

2007-2014

Main Variables
RE

FE

FD

RE

FE

FD

Model 1Model 2Model 3Model 4Model 5Model 6

C

165.96* (99.77)

180.54 (110.61)

1099.55*** (305.12)

1056.27*** (354.59)

ln 𝑌𝑖𝑡0.77** (0.32)

0.34 (0.93)

0.47 (0.73)

1.38*** (0.25)

1.98*** (0.51)

2.07*** (0.39)(𝐿𝑎𝑜𝑠)

4.25** (2.01)

4.96** (2.42)

4.31** (2.18)

24.45*** (6.19)

23.19*** (7.29)

18.40*** (3.79)

ln 𝐷𝑖𝑠𝑡𝑖 (𝑚𝑖𝑙𝑒)-1.48** (0.60)

ln 𝑅𝑃𝑖𝑗𝑡- 0.13*** (0.02)-0.14*** (0.03)-0.09*** (0.00)- 0.12 (0.09)

0.01 (0.54)-0.06 (0.26)

ln 𝑃𝑜𝑝𝑖𝑡

0.61*** (0.19)

0.57 (2.60)

0.03 (1.80)

0.84*** (0.17)-1.57 (2.51)-1.80 (1.57)

ln 𝑃𝑜𝑝𝑗𝑡 (𝐿𝑎𝑜𝑠)-12.52* (7.19)-14.10* (8.14)-11.63 (7.70)-81.62* (22.25)-76.87*** (25.34)-59.29*** (12.96)

𝑉𝑖𝑠𝑎04 × 𝐴𝑓𝑡𝑒𝑟04

0.28** (0.13)

0.286* (0.15)

0.29 (0.19)

𝑉𝑖𝑠𝑎05 × 𝐴𝑓𝑡𝑒𝑟05- 0.17 (0.48)-0.17 (0.54)

0.05 (0.15)

𝑉𝑖𝑠𝑎07 × 𝐴𝑓𝑡𝑒𝑟07- 0.02 (0.10)

0.02 (0.11)

0.17*** (0.03)

𝑉𝑖𝑠𝑎08 × 𝐴𝑓𝑡𝑒𝑟08

0.74** (0.05)

0.63*** (0.12)

0.17*** (0.07)

𝑉𝑖𝑠𝑎09 × 𝐴𝑓𝑡𝑒𝑟09

0.13** (0.04)

0.18*** (0.05)

0.05 (0.04)

𝑉𝑖𝑠𝑎11 × 𝐴𝑓𝑡𝑒𝑟11- 0.18*** (0.05)-0.14** (0.06)

0.02 (0.03)

𝑇ℎ𝑎𝑖 × 𝐴𝑓𝑡𝑒𝑟11

0.18*** (0.05)

0.144* (0.08)

0.11*** (0.03)

𝑇ℎ𝑎𝑖 × 𝐴𝑓𝑡𝑒𝑟13

0.18*** (0.04)

0.17** (0.06)

0.09** (0.03)

𝐶ℎ𝑖𝑛𝑎 × 𝐴𝑓𝑡𝑒𝑟13

0.20*** (0.05)

0.17 (0.11)-0.02 (0.04)

-

-

0.99

0.31

ln 𝑌𝑗𝑡-2.06*** (0.60)

𝑇ℎ𝑎𝑖 × 𝐴𝑓𝑡𝑒𝑟07

0.51*** (0.05)

0.54*** (0.08)

0.35*** (0.03)

𝑉𝑖𝑒𝑡 × 𝐴𝑓𝑡𝑒𝑟07

0.200*** (0.04)

0.19*** (0.07)

0.08*** (0.028)

𝑌𝑟01- 0.14*** (0.03)-0.14*** (0.03)-0.14*** (0.03)

𝑌𝑟03- 0.23*** (0.05)-0.23*** (0.05)-0.23*** (0.05)

𝑇ℎ𝑎𝑖

2.19** (0.94)

𝑉𝑖𝑒𝑡

0.89*** (0.24)

2.92*** (0.95)

𝐶ℎ𝑖𝑛𝑎

0.50 (0.70)

𝐴𝑓𝑡𝑒𝑟𝑡

Yes

𝑉𝑖𝑠𝑎𝑖

Yes

Sample Size

248

Adjusted R squared

0.571

-

Yes

217
0.98

253

0.40

0.667

* The level of statistical significance: ***1%, **5%, *10%. The numbers in parentheses are robust standard errors.

The coefficients of 𝑌𝑖𝑡 , 𝑌𝑗𝑡 , and 𝐷𝑖𝑠𝑡𝑖 are consistent with the hypothesis
assumed in the gravity model except of 𝑌𝑖𝑡 for 2000-2007. As mentioned above, theirresults demonstrate that the income level in an origin country (𝑌𝑖𝑡 ) promotes the travelto Laos as a push factor, the real GDP per capita in Laos (𝑌𝑗𝑡 ) represented as the qualityof the destination encourages the flow from foreign countries as the pull factor.
11

On thecontrary, the income level in an origin country doesn’t effect on the demand much for
2000-2007 in that the coefficient of 𝑌𝑖𝑡 is not large on RE model and not significant on
FE model and FD model. This result is similar with prior studies. Moreover, thedistance between two countries reduces the inbound demand as the travel expenditure.
𝑅𝑃𝑖𝑗𝑡 negatively influences the flow from origin countries as the other travel
cost in three models for 2000–2007. In our estimators, 𝑅𝑃𝑖𝑗𝑡 slightly reduced thenumber of tourists during 2000–2007 with statistical significance. On the other hand, it
did not show statistical significance during 2007-2014. This indicates that 𝑅𝑃𝑖𝑗𝑡 does
not influence much the determinant of foreign tourists. The efficiency of 𝑅𝑃𝑖𝑗𝑡 in the
result estimated by Phakdisoth and Kim (2007) is also not large (-0.072 ~ -0.087).
According to Phakdisoth and Kim (2007), because prices for goods or services andaccommodation in the less developed country are cheaper and the travel expenditure is
not very expensive, foreign tourists do not respond sensitively to the change in 𝑅𝑃𝑖𝑗𝑡 .
The coefficient of 𝑃𝑜𝑝𝑖𝑡 is not statistically significant in FE model and FDmodel, and that of 𝑃𝑜𝑝𝑗𝑡 significantly negative in most models. The signs of theirefficiencies in our results are similar to those by Lorde et al. (2015). As Lorde et al.
(2015) mention, countries with a small population experience physical and financial
constraints, so that many resources may not be invested into the tourism sector. On theother hand, as Lorde et al. (2015) do not interpret the sign of 𝑃𝑜𝑝𝑗𝑡 , the negative sign of𝑃𝑜𝑝𝑗𝑡 is against some previous studies mentioned above. One interpretation regarding
the result is that the population growth in origin countries can increase the potential
inbound tourists in Laos.
The disturbance of SARS in 2003 significantly decreased 0.235% of the inboundtourists compared with other years. Phakdisoth and Kim (2007) also show similar
results (-0.678 ~ -0.567) despite their usage of different time series data.
In following paragraphs, we will investigate results of the tourism policy. First,
we consider the results of the visa easing policy. The visa easing for Cambodia,
Malaysia, Singapore, Thailand, and Vietnam in 2004 significantly increased theinbound demand. In addition, the permission for the visa restriction for the Republic ofKorea in 2008 and for Switzerland and Myanmar in 2009 positively increased thenumber of flows from foreign countries. However, the visa easing in 2005 and 2007 was
not significant. The visa easing for Indonesia in 2011 had a significantly negative effectagainst the hypothesis, which may be related to the European financial crisis after 2011.
Secondly, we demonstrate the influence of constructing the friendship bridges
on tourism demand from neighboring three countries, Thailand, Vietnam and China. thecoefficients of 𝑇ℎ𝑎𝑖𝑙𝑎𝑛𝑑 × 𝐴𝐹𝑇𝐸𝑅07 , 𝑇ℎ𝑎𝑖𝑙𝑎𝑛𝑑 × 𝐴𝐹𝑇𝐸𝑅13 , 𝑉𝑖𝑒𝑡𝑛𝑎𝑚 × 𝐴𝐹𝑇𝐸𝑅07
are statistically significant and positive. However, we can’t clearly conclude that𝐶ℎ𝑖𝑛𝑎 × 𝐴𝐹𝑇𝐸𝑅13 effects on the inbound demand because it is not statisticallysignificant in FE model and FD model. As explained before, the second and fourth12friendship bridges are part of the economic corridors. Hence, their results of𝑇ℎ𝑎𝑖𝑙𝑎𝑛𝑑 × 𝐴𝐹𝑇𝐸𝑅07 , 𝑇ℎ𝑎𝑖𝑙𝑎𝑛𝑑 × 𝐴𝐹𝑇𝐸𝑅13 , 𝑉𝑖𝑒𝑡𝑛𝑎𝑚 × 𝐴𝐹𝑇𝐸𝑅07 imply the
economic effect of the economic corridor project on the tourism sector in Laos. Theirresults show that the construction of the four bridges to connect Laos with Thailand
contributes to the increase of foreign tourists from Thailand and Vietnam also has apositive impact on the growth of tourism.
Thirdly, the registration of the UNESCO World Heritage Sites in Laos in 2001
could not encourage the inbound demand, possibly because the global economy slowed
down during that time. Alternatively, one of the other reasons may have a difficulty toaccess these heritage sites from the center city in Champasak province. Also, thisHeritage has a rivalry to other UNESCO World Cultural Heritage Sites in neighboring
countries, such as “Angkor Wat” in Cambodia, “Hoi An Ancient town” in Vietnam, andthe “Ban Chiang Archaeological Site” in Thailand. Actually, the market share of tourists
in Champasak province are occupied with those of Thailand (almost 75% in 2014)
through three entry points (Vang Tao and Nong Nok Khain are the entry points on theland route, and the Pakse international airport). Thus, Thai tourists may not be muchinterested in this heritage site because the cultural and historical aspects between thetwo countries are similar.
Discussion
Taking the result of the panel data regression into account, this section discusses theinitiatives required for the long-term tourism growth in Laos. Wherever the research in
the tourism and hospitality fields discusses the long-term growth in the tourism sector,
the “tourist area life cycle” hypothesis by Butler (1980) is usually referred to. According
to this hypothesis, the growth in the tourists’ number has progressed like an S-shaped
curve over time, as shown in Figure 3. First, the rate of growth proceeds slowly, andthen increases rapidly. Eventually, the number of tourists becomes stable and thensubsequently declines as it exceeds the carrying capacity in the tourism sites. This
carrying capacity depends on several factors: environmental (e.g., water quality, air
quality, landscape), physical (e.g., transportation, accommodation, other public service),and social (e.g., crowding, discontent of the local community) (Butler, 1980).
Laos’s tourism may complete the development stage, referring to Figure 1, due
to the reduction of tourists in 2016, although we do not have accurate information onwhether the number in 2016 is accidental or not. As follows below, we suggest threechallenges that Laos’s government and the related administration should address so thatthe growth rate of tourist numbers can reach the rejuvenation path (A or B), and not thepath of decline (C, D, or E), after the stagnation stage.

13

Figure 3: A Tourist Area Cycle and Evolution

Number of Tourists

Stabilizationand subsequently decline

Rejuvenation

A
B

Stagnation
Critical Range ofElements of Capacity

C

Consolidation

D

DeclineE
Development

Rapid rate of growth

Involvement

Slowly rate of growth
ExplorationTime

Sources: Author’s own construction based on Butler (1980, p. 7, Figure 1)

First, it is necessary to allocate the benefit from the economic growth to thetourism sector and the related sectors for tourism growth in the future. As shown in theformer section regarding results of estimation, while the income level in Laos positively
influences the inbound demand, the population growth in the country decreases thenumber of foreign tourists. This is because small countries like Laos experience
physical and financial constraints as the population grows. Laos has to address thischallenge that the number of inbound tourists is somehow developed under theconstraint of population growth.
The first strategy could be to increase the skilled human resources in the tourism
sector because there are insufficient workers and experts in Laos’s tourism sector(Valentin & Schilcher, 2017). Moreover, Laos needs to improve the quality of the
tourism sector for long-term development. To enhance the quality of the tourism sectorin Laos, initiatives should be taken to invest in other sectors such as education andmedicine, to conserve natural resources in the ecotourism sites, and to develop
sustainably the regional economy in the tourism site and corroborate with the local
residents there. The construction of transportation for economic development, without
considering the sustainability in rural areas, could damage the natural environment anddecrease the rural economic growth while the urban economy grows. In order to avoid
such developments, the transportation project in GMS should aim for not only an“Economic Corridor” but also a “Green Economic Corridor” for sustainable
development. In this context, it is important to promote “alternative tourism” such as
ecotourism, cultural tourism, community-based ecotourism, and pro-poor tourism3, and14

to enforce the governance of the local administration against unsustainable
developments such as overexploitation, illegal logging, hunting, and corruption.
Second, to increase the number of tourists, Laos’s government needs tocooperate with neighboring countries and invest in transport infrastructure to connect tothese countries based on the results of the friendship bridge and the visa-permission
policy. In addition, Laos’s government should develop new tourism resources near theentry points and along the economic corridors to avoid any negative influence on theregional subsistence and the natural environment.
In addition, Laos should take initiatives to cooperate and collaborate with other
ASEAN countries. The visa easing had a significantly positive effect on six ASEAN
member countries (Cambodia, Malaysia, Singapore, Thailand, Vietnam, and Myanmar),but not on three countries (Philippines, Brunei, and Indonesia). Therefore, Laos’s
government needs to not only absorb more the inbound demand of the former six
countries but also develop another strategy for the latter three countries and release thevisa restriction for other countries that have not eased it as yet.
Third, Laos is bound to develop another tourism strategy to benefit from the
UNESCO World Heritage Site in Champasak, although the registration of “Vat Phouand Associated Ancient Settlements within the Champasak Cultural Landscape” as a
UNESCO World Heritage Site in 2001 does not noticeably increase the number offoreign travelers compared with that in other years. As indicated in the section regarding
results of estimation, this may be related to the economic crisis, the competition withneighboring UNESCO World Heritage Sites, or the few incentives for Thai travelers
who represent the maximum share in Champasak. Thus, the tourism sector in Laosneeds to devise other strategies such as a marketing strategy for Western foreigncountries, and a differentiation strategy for distinction from nearby cultural heritage
sites.
Conclusion
This paper examines the determinants of the inbound demand in Laos with the gravity
model, considering three interventions for tourism development: (1) visa easing, (2)development of economic corridors within GMS, and (3) the registration of UNESCOWorld Heritage Sites in 2001.
Our results can help discover the floating of the number of tourists from
Cambodia, Malaysia, Singapore, Thailand, Vietnam, and Myanmar after permitting visa
regulations, although we cannot find those from Philippines, Brunei, and Indonesia. In
addition, the construction of four friendship bridges between Laos and Thailand
encourages the inbound demand from not only Thailand but also Vietnam and China.
Because their bridge is located at key points in the East-West and South-North
15

Economic Corridors, their estimated results can be interpreted as the effect of theireconomic corridors on the tourism sector in Laos. However, we cannot confirm that theregistration of the UNESCO World Heritage Site in 2001 positively influences thedemand of foreign tourists.
Based on the results, this research suggests three actions required for long-term
growth in the tourism sector, considering the “tourist area life cycle” hypothesis of
Butler (1980). First, Laos should allocate the profits from economic growth for thesustainable development of the tourism sector. Second, Laos should necessarily
cooperate with neighbor countries and ASEAN countries for tourism development.
Third, Laos should develop another marketing strategy for promoting the UNESCOWorld Heritage site in the Champasak province.
The study has some limitations as well. This research analyzes the inbounddemand at only the whole country (macro) level. We have yet to examine the inbounddemand with the regional data to evaluate the tourism policy in detail. Laos has many
entry points, 31 points on land routes and four international airports, as of 2016
(Tourism Development Department, 2016). Indeed, each province has someheterogeneous characteristics at the provincial (micro) level (e.g., natural environment,
geography, culture, ethnic group, food). Future research could estimate the panel data
regression at the provincial level and analyze the destination marketing strategy of eachprovince for inbound tourism.
Acknowledgment: we highly appreciate the financial support from the JSPS KAKENHI Grant
Number JP16K16666 and Editage (www.editage.jp) for English language editing.

* The author belongs to Institute of Economic Research Chuo University (IERCU) as a visiting
researcher, and reported this paper in the public seminar hold by IERCU at 14 October, 2017.
1. We have the other reason to divide time series data into two terms. Actually, we attempt toestimate the panel data with the random model. However, E-views 9.5 shows the result that
random effects estimation requires more number of cross sections than number of coefficients for
between estimator for estimate of RE innovation variance. Therefore, this investigation deals withthis problem by separating time series data.
2. This may be due to the introduction of many dummy variables into the estimation.
3. There are some researches regarding “alternative tourism” in Laos at the regional or village
level. For example, refer to Travers (2007) about ecotourism; Khlaikaew (2015), Roverts(2015), Sosamphanh et al. (2013) about cultural tourism; Suntikul et al. (2009) about pro-poor
tourism; and Douangphosy et al. (2015) about community-based tourism.

16

References:
・ ASEAN Secretariat News (2013, May 22). Lao PDR Awarded World’s Best Tourist
Destination. Retrieved from http://asean.org/lao-pdr-awarded-world-s-best-touristdestination/.
・ Brunner, H. P. (2013). What’s economic corridor development and what can it achieve in Asia’s
subregion (ADB Working Paper Series on Regional Economic Integration No. 177). Retrieved
from https://www.econstor.eu/bitstream/10419/109610/1/wp-117.pdf.
・ Butler, R. W. (1980). The concept of a tourist area cycle and evolution: Implications for
management of resources. Canadian Geographer, 24(1), 5–12.
・ Culiuc, A. (2014). Determinants of international tourism (IMF Working Paper No. 82).
Retrieved from https://www.imf.org/external/pubs/ft/wp/2014/wp1482.pdf.
・ Douangphosy, B., Han C. H. & Ping, C. K. (2015). Community-Based Ecotourism for
Assessment Potential and Planning at Phou Khao Khouay National Protected Area, Lao PDR.
International Journal of Sciences, 4 (3), 1–8.
・ Fujimura, M. (2016). Evaluating impacts of economic corridors in GMS: Three different
approaches. Institute of Economic Research Aoyama Gakuin University Economic Review, 8,
39–55.
・ Greene, W. H. (2003). Econometrics analysis (5th ed.). Englewood Cliffs, NJ: Prentice Hall.
・ Hanafiash, M. H., & Harun, M. F. (2010). Tourism demand in Malaysia: A cross-sectional pooltime series analysis. International Journal of Trade, Economics and Finance, 1(1), 80–83.
・ Harrison, D., & Schipani, S. (2009). Tourism in the Lao People’s Democratic Republic. In M.
Hitchook, V. T. King, & M. Parnwell (Eds.), Tourism in Southeast Asia: Challenges and new
direction. Copenhagen: Nordic Institute of Asian Studies.
・ JETRO. (2015). 3rd survey on Mekong business needs and strategies in Mekong sub-reg
ion. Retrieved from https://www.jetro.go.jp/ext_images/_Reports/01/35a75139ecbb44ac/2015
0086_presentation.pdf.
・ Khalaikaew, K. (2015). The cultural tourism management under context of world heritage sites:
Stakeholder’s opinions between Luang Prabang communities, Laos and Muang-kao
communities, Sukhothai, Thailand. Procedia Economic and Finance, 23, 1286–1295.
・ Lee, D. (2007, December 9). The 53 places to go in 2008, New York Times. Retrieved fromhttp://www.nytimes.com/ref/travel/20071209_WHERE_GRAPHIC.html.
・ Lorde, T., Li, G. & Airey, D. (2016). Modeling Caribbean tourism demand: An augmented
gravity approach. Journal of Travel Research, 55(7), 1–11.
・ Massidda, C., & Etzo, I. (2012). The determinants of Italian domestic tourism: A panel data
analysis. Tourism Management, 33, 603–610.
・Ministry of Planning and Investment of Laos. (2017, July 4). The Friendship Bridge between
Laos and Myanmar is officially opened. Retrieved fromhttp://www.investlaos.gov.la/index.php/news-and-events/item/9-the-friendship-bridge-betweenlaos-and-myanmar-is-officially-opened.
17

・Morley, C., Rossello, J., & Santana-Gallego, M. (2014). Gravity models for tourism demand:
Theory and use. Annals of Tourism Research, 48, 1–10.

・ National Statistics Centre. (2006). 1975–2005 Basic statistic of the socio-economic
development in Laos. Vientiane: National Statistics Centre.
・ Nonthapot, S. (2016). Mediation between tourism contribution and economic growth in the
Greater Mekong Subregion. Asia Pacific Tourism Research, 21(2), 157–171.
・ Nonthapot, S., & Lean, H. H. (2013). Demand of Thai tourists to Lao PDR: An ARDL
approach. Asian Journal of Empirical Research, 3(3), 279–285.
・ Phakdisoth, L., & Kim, D. (2007). The determinants of inbound tourism in Laos. ASEAN
Economic Bulletin, 24(2), 225–237.
・ Roverts, N. (2015). The cultural and natural heritage of caves in the Lao PDR: Prospects andchallenges related to their use, management and conservation. The Journal of Lao Studies, (1),
113–139.
・ Sosamphanh, B., Yongvanit, S., & Apichatvullop, Y. (2013). Cultural landscape of the urban
community of Vang Vieng in the context of tourism. The Journal of Lao Studies, 4(1), 87–99.
・ Souliyong, S. (2017, February 11). Tour operators suggest activities for 2018 Visit Laos Year.
Vientiane Times. Retrieved fromhttp://www.vientianetimes.org.la/FreeContent/FreeConten_Tour_35.htm.
・ Suntikul, W., Bauer, T., & Song, H. (2009). Pro-poor tourism journal of tourism research. Asia
Pacific Journal of Tourism Research, 14(2), 153–168.
・ Susan, S., & Anna, S. (2010). Transport infrastructure and trade facilitation in the Greater
Mekong Subregion (ADBI Working Paper series No. 130). Retrieved fromhttps://www.adb.org/sites/default/files/publication/155985/adbi-wp130.pdf.
・ Tourism Development Department (2012). 2011 Statistical report on tourism in Laos. Retrieved
from http://www.tourismlaos.org/files/files/2011%20Statistics%20Report%20(English).pdf.
・ Tourism Development Department (2013). 2012 Statistical report on tourism in Laos. Retrieved
from
http://www.tourismlaos.org/files/files/2012%20Statistical%20Report%20on%20Tourism%20in%20English%20Version.pdf.
・ Tourism Development Department (2014). 2013 Statistical report on tourism in Laos. Retrieved
from
http://www.tourismlaos.org/files/files/2013%20Statistical%20Report%20on%20Tourism%20in%20English.pdf.
・ Tourism Development Department (2015). 2014 Statistical report on tourism in Laos. Retrieved
from
http://www.tourismlaos.org/files/files/2014%20Statistical%20Report%20on%20Tourism%20in%20English%20Version.pdf.
・ Tourism Development Department (2016). 2015 Statistical report on tourism in Laos. Retrievedfrom18http://www.tourismlaos.org/files/files/Statistic%20Report%202015%20Update%206%20June.p
df.
・ Tourism Development Department (2017). 2016 Statistical report on tourism in Laos. Retrieved
from http://www.tourismlaos.org/files/files/2016%20Statistic%20Report.pdf.
・ Travers, R. (2007). Economic Corridors and Ecotourism: Whither Tourism in Laos? In J.
Cochrane (Eds.), Asian Tourism: Growth and Change (pp. 106–116). Amsterdam: Elsevier.
・ Valentin, A., & Schilcher, D. (2017). Visiting oppressive states: Tourism in Laos, Cambodia and
Myanmar. In C. M. Hall & S. J. Page (Eds.), The Routledge Handbook of Tourism in Asia (pp.
205–220). Cornwall: Routledge.
・ WTTC. (2017). Travel & tourism: Economic impact 2017 Laos. Retrieved fromhttps://www.wttc.org/-/media/files/reports/economic-impact-research/countries2017/laos2017.pdf.
・ Yamauchi, S., & Lee, D. (1999). Tourism development in the Lao People’s Domestic Republic(DESA Discussion Paper No. 9). Retrieved from http://www.un.org/esa/esa99dp9.pdf.
Web site・ Lao Airline, Visa information. (https://www.laoairlines.com/?contentkey=pages&id=67)19