ABSTRACT
Chapter 12 presented issues relating to developing an overall picture of the values and costs of PAs at the site level, including the range of challenges related to developing such assessments and how to address them. This chapter focuses on aggregating benefits across a range of sites for a region or country, focusing on issues such as data availability and the choice of method to develop multi-site aggregates. Furthermore, the aggregation of benefits across multiple sites needs to consider the complementarity and/or competition between benefits across sites. This chapter explores the above issues offering guidance on what the challenges to developing multi-site aggregates are (Section 13.1) and how to develop aggregate values in practice with case examples to illustrate practical solutions (Section 13.2). The chapter is complemented by Chapter 14 on how to interpret the results.
