Trade unions are instrumental in bargaining for better wages and working conditions for their members. By doing so, they can counteract tendencies for wages to stagnate or decline, especially for lower and middle-income workers. In economies where trade unions are strong and have substantial representation, wage disparities tend to be lower. This is because unions work to reduce the wage gap between skilled and unskilled workers, and between executives and average employees. However, in places where union membership is on the decline or their influence is waning, the protective barrier against widening wage disparities may be compromised, potentially exacerbating income inequality.

The division of income between capital (returns on investments, property) and labour (wages) has significant implications for income inequality. Historically, labour's share of income has been relatively stable. However, recent trends indicate a declining share for labour in many countries. As capital becomes a larger contributor to income, and given that capital ownership is typically concentrated among the wealthier segments of the population, this shift can heighten inequality. Essentially, the rich, who receive more income from capital, get richer, while wage earners see a smaller proportion of the economic pie, widening income disparities.

Globalisation is a double-edged sword in the context of income inequality. On the positive side, it can open up markets, leading to job creation, especially in export-oriented sectors in developing countries, potentially lifting many out of poverty. Furthermore, the diffusion of technology and knowledge can improve productivity and wages in less developed regions. However, globalisation can also intensify competition, especially in low-skilled sectors, leading to job losses or wage suppression in certain industries. Additionally, it can lead to a 'race to the bottom' in labour standards if countries compromise on worker rights to attract investment. In essence, while globalisation has the potential to equalise incomes across countries, within countries, it can sometimes magnify disparities.

Education plays a cardinal role in shaping income distribution. It is an equalising force when accessible to all, as it improves the human capital of the workforce, enhancing productivity and potential income. However, when quality education is disproportionately available to the affluent, it perpetuates income disparities. Those with better education tend to command higher wages, leading to wage premiums associated with higher educational attainment. Moreover, in a technologically advancing world, the demand for skilled labour increases, exacerbating wage differentials. If education is not democratised, it can inadvertently widen the chasm between the haves and have-nots.

Income inequality can influence economic growth in several nuanced ways. On one hand, if the rich reinvest their wealth effectively, it can stimulate growth. However, excessive inequality can lead to a myriad of negative outcomes. It might curtail the potential of individuals from lower socio-economic backgrounds, thereby underutilising human capital. Moreover, high inequality can lead to lower consumer demand, as a larger proportion of the population may not have sufficient purchasing power. Furthermore, pronounced disparities can breed social unrest and instability, detracting from a conducive environment for investment and growth. Essentially, while some level of inequality might be growth-enhancing, beyond a threshold, it can stifle long-term economic prosperity.