In his magnum opus, 'Progress and Poverty', Henry George attempts to explain the causes of recessions and of poverty. Land is a crucial part of this. George believes the most important factor in poverty this is the ownership of land, a factor of production that is fixed in supply. The result of this limitation is that, while other factors can be increased or improved; land cannot. This makes it a very efficient and equitable tax. Instead of taxing labour or capital, we should tax land instead. This is a great work too often overlooked. His basic point is very good: the owners of land gain an economic rent from so doing. Such a rent provides a good source of government income.
If you are interested in a program to implement the work of Henry George, please see the Systemic Fiscal Reform group. http://systemicfiscalreform.org/