TY - RPRT A1 - Haan, Peter A1 - Sun, Chen A1 - Sunde, Uwe A1 - Weizsäcker, Georg T1 - Non-Additivity of Subjective Expectations over Different Time Intervals T2 - Berlin School of Economics Discussion Papers N2 - We examine the additivity of stock-market expectations over different time intervals. When asked about a ten-year interval, survey respondents expect a stock-price change that is not equal to, but closer to zero than, the sum of their expectations over two shorter time intervals that cover the same ten years. Such sub-additivity is irrational in that it cannot stem from aggregating short-term expectations. Model estimates show that the pattern is consistent with a time perception where shorter time intervals have a proportionally larger weight. We also find that the respondents’ degree of additivity is correlated with making larger financial investments. T3 - Berlin School of Economics Discussion Papers - 4 KW - Expectation Formation, Time perception, Sub-additivity, Super-additivity Y1 - 2022 UR - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b1570-opus4-46602 UR - https://berlinschoolofeconomics.de/insights/bse-discussion-papers ET - No. 4 ER -