How and why do political parties differ in their spending patterns? An empirical analysis of expenditure on party payroll staff

Despite the pivotal role of payroll staff within political parties' central offices, research on the staff expenses of parties remains scarce. In this article, we study the relative staff expenses of political parties, that is staff costs as a percentage of total annual expenses. We analyse which factors explain the differences between parties' relative staff expenses, based on a dataset of 590 individual observations representing 52 parties from seven European countries. The multivariate model shows that relative staff expenses are higher among left-oriented parties and that they increase with party age, party membership figures and the number of years a party has been in government, while they decrease with party income. Relative staff expenses also decrease with the effective number of parties in the party system, and they are lower in election years.