Happiness is a crucial human disposition that denotes a construct characterizing positive feelings in individuals and overall well-being. It can be perceived as a relatively stable state linked to diverse facets of an individual’s life and distinguishes itself from more transient emotions like joy or sadness. The comprehension of happiness holds significant importance in philosophical, psychological, scholarly, narrative, and governmental spheres, but conclusive agreement regarding the factors that genuinely engender happiness remains elusive. Happiness is “commonly understood as how much one likes the life one lives” . While the meaning and attainment of happiness may differ from person to person, levels of happiness also often fluctuate from one day to the next, and a pandemic such as COVID-19 is likely to change the dynamics of existing happiness.
1. Impact of Gross Domestic Product (GDP) on Happiness
Many studies have explored the relationship between happiness and gross domestic product (GDP) per capita, and the consensus is that there is a positive relationship between these two variables. A higher GDP per capita typically correlates with higher levels of happiness, at least up to a certain point.
A study of data from more than 100 countries found that GDP per capita was positively associated with happiness. That study concluded that this relationship was partially mediated by factors such as income inequality and social capital 
Similarly, according to a study from 2006, individuals in countries with higher GDP levels tend to report higher levels of happiness compared to those in countries with lower GDP levels. However, GDP is not the only determinant of happiness; other factors such as social support, personal freedoms, and cultural values also play roles in determining happiness levels 
Kahneman and Deaton found that when a country’s GDP per capita reaches about USD 25,000, further increases in GDP per capita do not lead to significant increases in happiness. Their study was based on Gallup World Survey data obtained from more than 450,000 respondents in 155 countries and their findings suggest that the relationship between income and happiness weakens beyond a certain income threshold. The authors suggested that other factors, such as social support, freedom, and health, become more important determinants of well-being as individuals reach higher income levels 
While there is a positive relationship between GDP per capita and happiness, the relationship is not always straightforward and there are important moderating factors, such as income inequality, that must be taken into account.
2. Impact of Social Support on Happiness
Social support refers to the resources that individuals receive from their social networks, such as emotional support, practical assistance, and companionship. There is a growing body of research examining the relationship between social support and happiness.
Nettle suggested that happiness can be considered on three levels. The first of these includes instant feelings such as joy and pleasure. The second level entails general contentment and satisfaction, while the third level involves individual self-actualization 
. Within this framework, it can be said that individuals with sufficient social support experience the first or second level of happiness. Social support from different sources ensures that an individual is not alone and feels stronger and more valuable. Therefore, social support positively affects the happiness of an individual.
According to Diener and Seligman, very happy people are more social and have stronger relationships. They are more likely to get married, have wider social networks, and receive more emotional support from others 
3. Impact of Happiness on Life Expectancy at Birth
There is a significant positive relationship between happiness and life expectancy at birth according to several studies. For example, according to Veenhoven’s extensive survey, people who consider themselves relatively happy within a country tend to live 7–10 years longer than those who describe themselves as unhappy 
. Levy, Slade, Kunkel, and Kasl reported a similar result for a sample of Americans aged 50 or older, even after controlling for the participants’ baseline levels of health. Their research suggests that happy Americans tend to live 7 years longer than those who are less happy, even at an age when people have established most of their fundamental habits 
In the early stages of economic development, even small economic advances yield substantial returns in various areas including calorie intake, clothing, housing, medical care, and ultimately life expectancy. However, when a society exceeds a certain development threshold, it reaches a point where further economic growth results in only marginal increases in both life expectancy and happiness. This nonlinear relationship between income and life expectancy is known as the Preston curve in honor of Samuel H. Preston, who first described it in 1975 
Pandemics are not only a medical phenomenon; they are also a social phenomenon that affects individuals and society on many different levels. A few months after the outbreak of the COVID-19 virus, many countries went into “lockdown” in response to the rapid spread of the virus and thousands of deaths 
. These lockdowns often closed businesses, making it necessary for individuals to stay home and/or work from home and avoid physical contact with others. Thus, the consequences of the virus have not only been physical (such as illness and hospitalization) and financial (such as redundancy, financial insecurity, and unemployment) 
but also possibly psychological, with impacts including fear and loneliness 
4. Impact of the Freedom to Make Life Choices on Happiness
The freedom to make one’s own life choices (FMLC) is often described as an important component of individual well-being and happiness. Several studies have examined the relationship between happiness and FMLC.
Inglehart et al. explored the relationship between happiness and economic development, as well as the role of freedom in contributing to happiness. They found that increases in FMLC were positively associated with higher levels of happiness 
According to Brulé and Veenhoven, the variations in average happiness among wealthy nations can be attributed largely to differences in freedom. This includes not only perceived freedom but also actual freedom, and particularly psychological freedom. The reason why Finns are happier than the French, for instance, is that they feel freer and are freer. This increased actual freedom is not simply due to less restrictive policies in Finnish society but also to a greater willingness to pursue personal freedom 
5. Impact of Generosity on Happiness
Generosity can be defined as the willingness to give time, money, or other resources to others without expecting anything in return. Research suggests that there is a positive relationship between happiness and generosity.
Aknin, Proulx, and Dunn conducted a study in which they gave participants money and instructed them to either spend it on themselves or on others. They found that participants who spent the money on others reported higher levels of happiness than those who spent the money on themselves 
Nelson, Layous, Cole, and Lyubomirsky conducted a study in which they instructed participants to perform five acts of kindness over the course of a day. They found that participants who performed those acts of kindness reported increased happiness compared to a control group 
In parallel with these studies, Diener and Seligman suggested that very happy people are more altruistic and engage in more prosocial behavior. They are more likely to volunteer, donate to charity, and help others in need 
6. Impact of the Perception of Corruption on Happiness
The perception of corruption can be defined as the degree to which individuals perceive corruption to be prevalent in their society. Research suggests that there is a negative relationship between happiness and the perception of corruption. Corruption is often seen as a barrier to social and economic progress and it undermines social trust and cooperation, which can negatively impact well-being.
According to Ma et al. 
, perceptions of official corruption are negatively related to subjective well-being. Corruption tends to lower income and it is one of the most important generators of poverty 
. On the micro level, personal experiences of corruption can influence an individual’s happiness. Experiences of corruption have detrimental effects on individuals’ mental health. Thus, corruption can undermine citizens’ happiness, but governments can remedy those negative impacts by improving government performance 
7. Impact of Confidence in the National Government on Happiness
Confidence in the national government can be defined as the degree to which individuals have trust and confidence in their country’s government and political institutions. Several studies have shown a positive correlation between happiness and confidence in the national government. In other words, people who have higher levels of trust in their government tend to report higher levels of happiness and life satisfaction.
For example, a study conducted by Inglehart and Klingemann in 2000 analyzed data from the World Values Survey and found that people who trusted their national government were more likely to be happy than those who did not 
. Similarly, Helliwell and Huang analyzed data from the World Values Survey and found that confidence in government was positively associated with happiness, even upon controlling for other factors such as income and social support 
Another study by Oishi and Schimmack used data from the Gallup World Poll to examine the relationship between trust in government and subjective well-being in 129 countries. The authors found that trust in government was positively related to life satisfaction and emotional well-being, and this relationship was consistent across different cultures and economic systems 
In another previous study, the relationships between respondents’ subjective well-being and confidence in six institutions were assessed in ten South American countries. Confidence in national institutions was significantly positively associated with both types of life satisfaction and the relationships persisted after controlling for sociodemographic and macroeconomic factors 
Overall, these studies suggest that confidence in the national government is an important predictor of happiness and well-being at both individual and societal levels.