ICRG compiles monthly data on a variety of political, financial and economic risk factors to calculate risk indices in each of these categories as well as a composite risk index. Five financial, thirteen political and six economic factors are used. Each factor is assigned a numerical rating within a specified range. The specified allowable range for each factor reflects the weight attributed to that factor. A higher score indicates lesser risk.Political risk assessment scores are based on subjective staff analysis of available information. Political Risk Services is the most widely accepted system of completely independent political risk forecasting.There is a organization call International Country Risk Guide (ICRG),  it provided expert financial, political and economic risk analysis for investors and international business professionals. The ICRG evaluates both the obvious developments and the subtle factors that cursory annual reviews all too frequently miss.Therefore by having this services, the investors who want  to invest overseas will have a better idea of which kind of risk they will be facing. Reference:< http://www.prsgroup.com/PRS.aspxhttp://www.duke.edu/~charvey/Country_risk/pol/pol.htm