Over the past two decades, international tourism has developed rapidly and it is one of the fastest-growing industries in the world (Habibi, 2017; Ovat, 2003). Developing the tourism sector has been identified as a way for a nation to diversify its economy, increase foreign exchange earnings, create job opportunities, boost infrastructural development, promote private investment, enhance structural transformation of rural areas, and foster sustainable economic growth and development (Ajani et al., 2018; Awode, 2022; Bankole & Odularu, 2006; Jalil et al., 2013; Mariyono, 2017; Oh, 2005; Olorunfemi & Raheem, 2008; Ovat, 2003). In 2018, tourism contributed 10.4% to global GDP, 30% to global service exports, and 10% to global jobs, with an estimated 1.4 billion tourist arrivals. The number is projected to reach 1.8 billion in 2030 (Awode, 2022; World Tourism Organization, 2019).

Nigeria is endowed with rich cultural festivals, ecotourist attractions and sites of interest across the country’s six geopolitical zones, potentially making it one of the greatest tourist destinations in the world (Napoleon, 2021; Orekoya, 2018). Its festivals include the Arugungun Fish Festival in the Northwest, the Calabar Carnival in the Southsouth, and the Eyo and Ojude Oba festivals in the Southwest. Among the nation’s rich ecotourist sites are the Northcentral’s Borgu Game Reserve, Kainji Lake National Park, Mambilla Plateau and Zuma Rock, the Northeastern’s Yankari Game Reserve, Oguta Lake in the Southeast and the Obudu Mountain Resort in the Southsouth. Other noteworthy sites include Alpha Beach, Badagry Beach, Bar Beach, Eleko Beach, Old Oyo National Park, Olumo Rock, Osun-Osogbo Sacred Grove, and Ikogosi Warm Spring in the Southwest (Jemirade, 2021; Orekoya, 2018).

Despite the enormous potential of these natural resources, Nigeria has not managed to earn substantial tourism revenues (Jemirade, 2021). More worrisome still, Nigeria lags behind relatively poorer African nations in terms of tourist arrivals and income (Andzenge, 2021; Awode, 2022; Jemirade, 2021). Recognizing the benefits of tourism, successive governments have taken steps to address prior failures and reposition the sector (Akwara et al., 2014; Awode, 2022; Jemirade, 2021). For instance, the early Nigeria Tourist Association (NTA) Decree 54 of 1976 was replaced by the Nigerian Tourist Board (NTB) Decree 54 of 1979. Then in 1989, the Department for Tourism was created within the Ministry of Trade, which became the Ministry of Trade and Tourism. Also, the federal government encouraged participation and synergy among key stakeholders such as the National Parks Commission, the Nigeria Conservative Fund, the Federal Ministry of Culture and state counterparts, and the National Tourism Development Cooperation to promote tourism. Recently, the Nigerian Immigration Service launched a ‘visa on arrival’ policy for short visits by African Union (AU) member-nations passport holders. These and other initiatives have sought to boost activity in the tourism sector.

Government efforts notwithstanding, little has been achieved in harnessing the sector’s potential. Tourism in Nigeria is plagued by inadequate funding, an information and promotion gap, low quality personnel and entrepreneurial skills, poor infrastructures (roads, electricity and water supply), low hotel standards, poor and inconsistent policy implementation, political instability, ethno-religious conflicts, insecurity, corruption and the country’s negative image abroad (Akwara et al., 2014; Andzenge, 2021; Bankole & Odularu, 2006; Buba et al., 2020; Ezenagu, 2018; Jemirade, 2021; Napoleon, 2021). All these affect the nation’s capacity to earn significant revenue from tourism.

The World Bank’s World Development Indicators (WDI) for Nigeria during the 1996-2020 period indicate unsteady, fluctuating tourism receipts as measured (in US$) by aggregate tourism receipts (expenditures by international tourists, expenses to national carriers for international transport, pre-payments on goods and/or services received by the host nation, and receipts from same-day tourists), revenue from passenger transport items (international tourists’ expenditure on international transportation services rendered by host-nation’s carriers, payments for passenger services performed within an economy by non-resident carriers, passenger fares, package tour payments), and travel items receipts (international tourist expenditure in the destination country, goods or services purchased by or for tourists or provided without quid pro quo for tourists to use or give away, including pre-payment on goods and services received in the host nation and payments by same-day visitors) (Figure 1). This instability has negative consequences on sector development and the economy as a whole.

Figure 1 Figure 1. Tourism receipts for Nigeria (1996–2020) Source: Author’s computations based on WDI data.

Nigeria and other African countries are among those who benefit least from international tourism. They also face insecurity and corruption challenges which can hinder development of the tourism industry (Jemirade, 2021; Jimoh & Gold, 2019; Sifolo, 2016). Corruption is considered an obstacle to tourism development because it increases the costs to tourists, who are asked to pay bribes to obtain visitor permits, speed-up visa application processing, facilitate access to restricted sites and activities that require government approval, or who are obliged to spend more hours or days than intended for their visit or holiday (Poprawe, 2015; Xu et al., 2023; Yap & Saha, 2013). Authors have expressed concern about increasing corruption and its devastating impact on different sectors of Nigeria’s economy (Abu et al., 2023; Abu & Karim, 2021; Abu, Obi, et al., 2024; Abu, Karim, et al., 2022). In fact, Andzenge (2021) blamed corruption for underdeveloped tourism in Nigeria, because funds allocated to promote it have been embezzled or cchronically mismanaged over time by public officials (Jemirade, 2021).

Insecurity stemming from terrorism, violent attacks, bombings, kidnappings, abductions, and (ritual) killings has also been on the rise in Nigeria. Insurgents (Boko-Haram) have been ravaging the Northeast, resulting in killings, property destruction and displacement of people. Similarly, cattle rustling, kidnappings and abductions have increased in the Nothwest and are gradually spreading to other parts of the nation. The Southeast is under siege by the Indigenous People of Biafra (IPOB), and cult activities across the Southern region make it relatively unsafe. Ritual killings and herder-farmer conflicts are also observed from time to time across the country.

Daily reporting of such activities (crimes) in the media raises fear and feelings of insecurity in the population, which tends to dissuade potential tourists (Garofalo, 1979; Tang & Tan, 2015). Researchers claim that potential visitors are likely to postpone or cancel travel if the destination is perceived as insecure or unsafe, or opt for destinations with greater guarantees of personal safety or security (Brunt et al., 2000; Kővári & Zimányi, 2010; Pizam, 1999; Ryan, 1993; Sönmez & Graefe, 1998; Tang & Tan, 2015). Rising insecurity may have impacted the tourism sector negatively because prospective tourists or visitors feel Nigeria is unsafe (Awode, 2022; Buba et al., 2020; Ezenagu, 2018; Jemirade, 2021).

Despite the high insecurity and corruption and the relatively underdeveloped tourism sector, only a few empirical studies have considered a relation between corruption and tourism or insecurity and tourism in Nigeria (Awode, 2022; Riti et al., 2017; Osinubi et al., 2021). Research exploring the joint influence of corruption and insecurity on tourism development in Nigeria is even more scarce. Riti et al. (2017) used Autoregressive Distributed Lag (ARDL) to look at the impact of insecurity on Nigerian tourism. They found that rising insecurity deterred foreign tourists intending to visit Nigeria. Using a similar method (i.e., ARDL), Alola et al. (2019) reported that insurgency had a negative influence on Nigeria’s tourism receipts. Awode (2022) applied the Fully Modified Ordinary Least Squares (FMOLS) method and found a significant positive influence of greater security on tourism in Nigeria. Other ARDL-based research by Osinubi et al. (2021) suggested that reducing corruption boosted tourism activity in Nigeria.

We believe that we can improve upon the commendable efforts of these authors. The ARDL and FMOLS techniques they used estimate only linear relation(s) between or among variables, but recent revelations imply that non-linear relations often occur between dependent variable(s) and regressors (Shin et al., 2014). Whereas most research on the demand for tourism and its drivers have been explored within a linear framework, volatility and structural changes cannot be ascertained via linear models (Meo et al., 2018; Po & Huang, 2008). Moreover, since the demand for tourism is influenced by asymmetries, ignoring non-linearity in economic relations can lead to inaccurate inferences (Meo et al., 2018; Smeral, 2012).

To our knowledge, none of the existing research on the determinants of tourism demand in Nigeria have studied these dynamics within an asymmetric framework. In this study, we deployed non-linear ARDL (NARDL) to uncover how negative and positive changes in (or shocks to) regressors (such as corruption and insecurity) impact the dependent variable (tourism development). In addition, using large number observations in the present research (relative to the ones employed by prior studies on Nigeria) might lead to better results generation.

The remainder of the study is organized as follows: Section Two reviews studies on the corruption-tourism and insecurity-tourism nexuses, while Section Three describes the theoretical underpinning and the model. The fourth section contains the methodology, and the results are discussed in the fifth section. Section Six concludes the study.

Although studies on the corruption-tourism or insecurity-tourism nexus abound, empirical research on separate or combined influence of insecurity and corruption on Nigeria’s tourism development is scarce. The few existing studies for Nigeria have explored either one dynamic or the other, but not both. Some studies have looked for a negative influence on tourism from insecurity in the form of bombings, crimes, violent attacks and terrorism, at the country-specific level (Alola et al., 2019; Buigut & Amendah, 2016; Chi, 2015; Choyakh, 2009; Fletcher & Morakabati, 2008; Habibi, 2017; Hanon & Wang, 2020; Khan & Rasheed, 2016; Mariyono, 2017; Omer & Yeşiltaş, 2020; Parida et al., 2016; Riti et al., 2017) and multi-country level (Altindag, 2014; Buigut, 2015; Fourie et al., 2020; Jimoh & Gold, 2019; Joshi et al., 2017; Saha et al., 2017; Santana-Gallego & Fourie, 2020; Tang & Tan, 2015; Yang et al., 2010). Most report that tourism activity or development declines with rising insecurity.

Other studies on the influence of corruption on the tourism industry in individual country (Chulaphan & Barahona, 2021; Osinubi et al., 2021) or a group of nations (Das & DiRienzo, 2010; Jimoh & Gold, 2019; Poprawe, 2015; Xu et al., 2023) have established that decreased corruption promotes tourism development. Table 1 presents a summary of the relevant literature.

Table 1

Corruption and tourism
Author(s)	Country(ies)/Period	Method/Model	Major Findings
Xu et al. (2023)	30 African countries (1996-2020)	FE and PCSE	Worsening corruption reduces tourism development
Osinubi et al. (2021)	Nigeria (2002Q1 to 2018Q4)	ARDL	Corruption hurts tourism development
Chulaphan and Barahona (2021)	31 countries (2010-2017)	ARDL and GLS	Corruption has a negative impact on tourism
Jimoh and Gold (2019)	ECOWAS (2000-2015)	Pooled OLS, FE and RE	Reducing corruption fosters tourism growth
Fourie et al. (2020)	171 countries (1995-2016)	Panel FE	Declining corruption enhances tourism growth
Poprawe (2015)	Over 100 countries (1995-2010)	FE and GMM	Reducing corruption boosts tourism sector growth
Yap and Saha (2013)	139 countries (1999-2009)	Panel FE	Corruption slows down tourism development
Das and DiRienzo (2010)	119 countries (From 2006)	OLS	Less corruption promotes tourism competitiveness across nations
Insecurity and tourism
Author(s)	Country(ies)/Period	Method/Model	Major Findings
Santana-Gallego and Fourie (2020)	187 countries (1995-2017)	PPML	Insecurity hinders the growth of the tourism sector
Jimoh and Gold (2019)	ECOWAS (2000-2015)	Pooled OLS, FE and RE	Higher security fosters the growth of tourism
Fourie et al. (2020)	171 countries (1995-2016)	Panel FE	Insecurity (terrorism and crime) hinders the growth of tourism
Awode (2022)	Nigeria (2022)	FMOLS	Greater security boosts tourism activity
Alola et al. (2019)	Nigeria (2005M1-2016M12)	ARDL	Insecurity (terror attacks) has an adverse effect on tourism receipts
Riti et al. (2017)	Nigeria (1996-2014)	ARDL/VECM	Insecurity hurts tourism
Mariyono (2017)	Indonesia (2002-2011)	Panel regression	Greater security boosts tourism
Habibi (2017)	Malaysia (2000-2012)	GMM	The absence of violence and terrorism encourage tourism
Buigut and Amendah (2016)	Kenya (2010-2013)	System-GMM	Insecurity (terrorism) deters tourists and lowers tourism revenue
Parida et al. (2016)	Indian (1995-2011)	IV-2SLS	Rising insecurity (crime) constitutes a barrier to tourism growth
Khan and Rasheed (2016)	Pakistan (1972-2013)	ARDL	Terrorism has adversely affected tourism
Altindag (2014)	35 European nations (1996- 2003)	Panel regression	Decreased security (rising crime) deters tourists and lowers revenue from tourism
Pizam and Fleischer (2002)	Israel (1991-2001)	Least Squares regression	Terrorism causes greater decline in tourism

Note

PPML: Poisson Pseudo Maximum Likelihood; ARDL: Autoregressive Distributed Lag; FE: Fixed Effects; GMM: Generalized Method of Moments; PCSE: Panel Corrected Standard Errors; RE: Random Effects; OLS: Ordinary Least Squares; FMOLS: Fully Modified OLS; IV: Instumental Variable; 2SLS: Two Stage Least Squares; GLS: Generalized Least Squares (GLS).

The present study contains three features that set it apart from the existing research on Nigeria. Most prominently, it is the first empirical research to explore the influence of both insecurity and corruption on the development of tourism in Nigeria. Also, our study uses a non-linear ARDL method to explore long-term positive and negative (asymmetric) impacts of insecurity and corruption on tourism development. Finally, the expanded study period and the use of quarterly data for the entire 1996-2021 period has allowed for substantial more observations.

To model the impacts of corruption and insecurity on tourism development, this research relies on the theories and hypotheses of prior studies. For instance, the ‘grease-the-wheels’ and ‘sand-the-wheels’ hypotheses (Dreher & Gassebner, 2013; Méon & Sekkat, 2005) have been extended to the study of the corruption–tourism development nexus (Poprawe, 2015; Xu et al., 2023; Yap & Saha, 2013).

According to the first hypothesis, international tourists may be required to ‘grease the wheels’ by paying bribes (act of corruption) to government officials (such as immigration personnel) in the destination-country to make it easier for them to obtain a visa or collect visitors’ permits without delays (Xu et al., 2023). Tourists may also offer bribes to facilitate access to better hotel rooms, restricted sites and activities requiring government approvals, or to spend more hours or days than originally intended for their visit or holiday (Poprawe, 2015; Yap & Saha, 2013). In this way, corruption could actually boost the inflow of tourists, leading to higher tourism receipts or revenues and development.

The ‘sand-the-wheels’ hypothesis argues that offering or paying bribes to obtain visitors’ permits, speed up visa processing, gain access to better hotel rooms or other services increases the costs of visiting the destination-country. This deters international tourists, causing them to look in countries with less corruption. Thus, high corruption would lower the volume of inbound tourists and associated revenues. The claim that corrupt nations attract little foreign direct investment (FDI) inflow to their tourism industry is consistent with this line of thought (Fan et al., 2009; Poprawe, 2015). Together, these arguments imply that tourism development (TOUR) can be affected positively or negatively by corruption (COR)

Insecurity (INS) in the destination-country may also influence tourism, as potential tourists prioritize personal safety when deciding whether to travel to a destination country (Altindag, 2014). Accordingly, individuals are highly likely to visit countries they consider secure and safe. Inversely, potential tourists are deterred from visiting countries they perceive as unsafe or risky, or where the likelihood of insecurity is high. Crime and related activities tend to reduce the number of incoming tourists and associated receipts (Altindag, 2014; Awode, 2022; Feridun, 2011; Fleischer & Buccola, 2002; Pizam, 1999; Pizam & Fleischer, 2002; Smyth et al., 2009). Thus, rising insecurity hinders tourism development.

Additionally, the income level (GDPCG) of the destination-country can dictate the amount of tourists it can attract and the revenues that can be generated (Leitão, 2009; Saha & Yap, 2013; Tang & Tan, 2015; Yang et al., 2010; Yap & Saha, 2013). Income level signifies the minimum cost for tourists who visit the destination-country. Income level is also used to measure economic wellbeing and performance, including the capacity of the destination-country’s government to maintain existing tourism infrastructures while investing in and building new ones (Saha & Yap, 2013; Yap & Saha, 2013). Hence, rising income or GDP growth promotes tourism development.

Infrastructure development (INFR) is also critical to tourism development. Better infrastructure raises investment productivity and attracts FDI to a country (Asiedu, 2002; 2004). The higher economic growth rates that accompany increased FDI inflow result in development of the tourism industry (Adeola & Evans, 2020; Xu et al., 2023; Zhang & Zhang, 2016). Similarly, a nation’s exchange rate (EXC) can impact its tourism receipts (Jayaraman et al., 2011; Kusni et al., 2013; Saha et al., 2017). The exchange rate determines relative prices of tourism between a traveler’s home country and the destination-country (Lim, 2006; Saha et al., 2017). If Nigeria’s domestic currency (Naira) is weaker compared to other countries’ currencies, foreign tourists will spend less to visit the country. Thus, depreciation of domestic currency will raise the number of incoming tourists and tourism revenue in a country, resulting in the sector’s development.

Based on the above discussion, we developed a tourism development (TOUR) model that has corruption (COR ), insecurity (LINS ), income (GDPCG ), infrastructure (NFR), and exchange rate (LEXC) as regressors as follows:

(1) LTOURt=α0+α1CORt+α2LINSt+α3GDPCGt+α4INFRt+α5LEXCt+εt

where L is the logarithm included to give the series identical scale and reduce skewness.

This study concentrates primarily on exploring long-term asymmetric impacts of insecurity and corruption on Nigeria’s tourism development, based on application of the NARDL method to quarterly data from 1996 to 2021. The cointegration test result provides an evidence of long-term relation among corruption, insecurity and tourism development, alongside income, infrastructure and the exchange rate. The asymmetry test results imply long-run non-linear relationship between tourism and corruption, as well as between tourism and insecurity. The coefficient of the positive shock to control of corruption was positive and significant, while the coefficient of a negative shock to control of corruption was insignificant over the long-run. The coefficient of the positive shock to insecurity was also significant and negative, but the coefficient of the negative shock to insecurity was significant and positive in the long-run. The estimation results suggest that a decline in corruption aids long-term tourism development, while rising insecurity would inhibit long-term tourism development. Also, depreciation of the domestic currency seems to enhance long-term tourism development. Thus, policies that reduce corruption and insecurity will stimulate long-term tourism development in Nigeria.

In light of these findings, government should strengthen the fight against corruption through appropriate and adequate funding of the agencies and institutions tasked with tackling graft, by establishing an efficient judiciary system and by increasing international collaboration. As corruption diminishes, the costs of travelling and visiting Nigeria will decrease, leading to more tourist arrivals and increased revenue from tourism activities. Also, there is a need for greater government commitment to reduce the high insecurity the nation is facing. This can be achieved through increased funding of the military, police and other national security forces, and higher investment in intelligence gathering, which appears to be absent in the ongoing war against non-state actors and perpetrators of crimes. The feeling of safety that accompanies greater security will encourage prospective tourists to visit Nigeria, and the sector will develop. Further, although depreciation appears to boost tourism activities, recommending further devaluation or depreciation of the domestic currency would only worsen the already precarious situation in Nigeria and negatively impact citizens well-being. But pursuing a policy of a stable exchange rate can raise confidence in the Nigerian economy, attract foreign tourists and investors, and consequently promote tourism development. Measures to raise investment in infrastructure and income level can also assist the fight against corruption and insecurity, to promote tourism development in Nigeria in the long run.

While this research has uncovered the long-term asymmetric impacts of insecurity and corruption on tourism development in Nigeria, it has some limitations that future studies can address. First, the present study uses only one measure of insecurity (i.e., expenditure on internal security). Future research could use different proxies for insecurity (such as the number of persons killed by violence, kidnapping, insurgent activity, bombings, etc.) to see how each impacts tourism. Similarly, this research employs a single measurement for corruption (i.e., the control of corruption). Future studies should incorporate other corruption measurements such as the Transparency International Corruption Perception Index (CPI) and the ICRG Control of Corruption. Finally, future research should involve the use of additional estimation techniques, such as threshold NARDL, to see the level above (or below) which corruption and insecurity can promote or hurt tourism development in Nigeria.