Participate in NGA’s Global Payroll Complexity Index Mar 27, 2019 - Human Resources Are you an HR or payroll expert? Participate in NGA’s Global Payroll Complexity Index! The GPCI provides an independent overview of payroll complexity per country and highlights the major challenges. It provides the visibility organizations need to minimize the risk and complexity of managing multi-country payroll. This content is only for paying members. Are you a member yet?. Click here to login. Do you want to become a member?. Click here to register.