The correlation matrix.

Income inequality is an essential cause of violence, stagnant development, and political instability. This study will examine the positive and negative shocks in tourism development, and the distribution of the interaction between tourism development, economic growth, human capital, globalization, and income inequality will be discussed in Singapore, a developed and top-visited country. By adopting autoregressive distributed lag and non-linear autoregressive distributed lag approaches for panel data from 1978 to 2022, the results indicate an asymmetric cointegration among variables, and positive and negative changes in tourism development lead to decreased income inequality. More specifically, the asymmetric effect of tourism is found both in the short- and long-term, and positive shock has a greater impact than negative shock. At the same time, the findings also reveal that economic growth and globalization enhance, while human capital negatively affects income inequality in Singapore. These findings strengthen the belief of Singapore policy-makers and recommend several significant lessons for developing countries to promote tourism, sustainable development, and reduce income inequality.