The informal sector is core to the growth and livelihoods of many economies and is seen as both a highly dynamic sector and a fragile one. It provides significant amounts of employment across the world but the quality of this employment is often problematic, with employment in this sector characterised by ‘small or undefined work places, unsafe and unhealthy working conditions, low levels of skills and productivity, low or irregular incomes, long working hours and lack of access to information, markets, finance, training and technology’. As with all areas of regulatory control, there are two types of environmental regulation policies: command and control policies and economic incentives. Many studies suggest that informal economic activity should be formalised. Since pollution is an externality from production, government attempts to reduce it often take the form of taxes on pollutants and subsidies on the disposal of waste. This chapter presents an overview on the key concepts discussed in this book.