TY - CHAP AB - Lewbel and Pendakur (2009) developed the idea of implicit Marshallian demands. Implicit Marshallian demand systems allow the incorporation of both unobserved preference heterogeneity and complex Engel curves into consumer demand analysis, circumventing the standard problems associated with combining rationality with either unobserved heterogeneity or high rank in demand (or both). They also developed the exact affine Stone index (EASI) implicit Marshallian demand system wherein much of the demand system is linearised and thus relatively easy to implement and estimate. This chapter offers a less technical introduction to implicit Marshallian demands in general and to the EASI demand system in particular. I show how to implement the EASI demand system, paying special attention to tricks that allow the investigator to further simplify the problem without sacrificing too much in terms of model flexibility. STATA code to implement the simplified models is included throughout the text and in an appendix. VL - 288 SN - 978-1-84855-313-2, 978-1-84855-312-5/0573-8555 DO - 10.1108/S0573-8555(2009)0000288010 UR - https://doi.org/10.1108/S0573-8555(2009)0000288010 AU - Pendakur Krishna ED - Daniel J. Slottje PY - 2009 Y1 - 2009/01/01 TI - Chapter 7 EASI Made Easier T2 - Quantifying Consumer Preferences T3 - Contributions to Economic Analysis PB - Emerald Group Publishing Limited SP - 179 EP - 206 Y2 - 2024/09/24 ER -