1. KPA Ltd., Raanana 43100, Israel;
2. Department of Mathematics, University of Turin, 10124 Turin, Italy
3. The Samuel Neaman Institute, Technion 32000, Israel
4. Israel Central Bureau of Statistics, Jerusalem 95464, Israel
5. Department of Statistics, Hebrew University, Jerusalem 91905, Israel
6. Department of Social Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
7. Department of Statistics and Operations Research, Tel Aviv University, Tel Aviv 69978, Israel