<p><p><p><p><p><p><p><p>This presentation was delivered at the IFS Residential Conference 2007. </p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p><em class="bold">PLEASE NOTE</em>: this presentation represents draft work in progress. Factual accuracy is not guaranteed, and opinions may not be the fully formed views of authors. They are posted here to stimulate discussion, and should not be quoted or cited without the authors' permission.</p></p></p></p></p></p></p></p></p>