For those who do not have formal jobs but engage in some form of monetary economic activity, it is of analytical importance to be able to measure this part of economy. This part of economy is known as the informal economy. The informal economy may be observable or unobservable, but it does not mean that they are illegal. For example: street vendors or online ride-booking service drivers may be unobserved and informal, but they are likely to be legally taxed. The production of informal economy has developed in varying ways in different countries. The informal economy is likely to be encouraged if the motive is simply to survive or just to achieve a flexible working style.