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Mathematical Models & Movies: A Sneak Preview. Ron Buckmire ron@oxy.edu Occidental College Los Angeles, CA. Outline. Introduction to Cinematic Box-Office Dynamics Important variables and concepts Graphs of typical movie data Presentation of Edwards-Buckmire Model (EBM) Drawbacks of EBM
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Mathematical Models & Movies: A Sneak Preview Ron Buckmireron@oxy.eduOccidental College Los Angeles, CA
Outline • Introduction to Cinematic Box-Office Dynamics • Important variables and concepts • Graphs of typical movie data • Presentation of Edwards-Buckmire Model (EBM) • Drawbacks of EBM • Derivation of Modified EBM • Numerical Results Using Modified EBM • Future (and Past) Work • The Holy Grail: A Priori Prognostication • Sequels: Parent-Child Relationship • Conclusions • References and Acknowledgements
Introduction: Cinematic Box-Office Dynamics Important variables • G(t) : cumulative gross receipts of the movie • S(t) : number of screens movie is exhibited • A(t) : normalized weekly revenue ($ per screen average) • t : time in number of weeks Important concepts • A and S have quasi-exponential profiles
Dimensionless EBM where
Drawbacks of EBM • H% varies with time • Parameter () estimates are difficult to make and somewhat arbitrary • Most movies have a contract period in which screens is constant, i.e.S’=0 • S and A actual data more erratic than first thought; G is relatively smooth
Modifying the EBM (J. Ortega-Gingrich) • Uses an Economics-inspired “demand” model • Incorporates fixed contract periods when screens are constant • Greatly modifies the A equation • Both versions of EBM have 3 unknown parameters
Deriving the new A equation Recall that G’=SA and assume that G could satisfy the IVP Which leads to and Consider a Demand function D(t)=S(t)Ap(t) which satisfies Where Ap is the revenue per screen if everyone whowanted to see the film, saw it, i.e. “A potential”
The functionμ(S) should satisfy the following conditions The selected form ofμ(S) used is given below (a=1/T), T is total number of movie theaters in North America (~4,000)
Derivation: Doing The Math We apply the product rule to A and Ap
Numerical Calculations • Analyzed119 movies from 2005-2010 (minimum final gross $50m) • All dollars adjusted for inflation to 2005 • Used Mathematica to generate numerical solutions to the modified EBM • Attempted to find “global” values of parameters that would minimize std. dev. in difference between computed G∞ and actual G∞ while minimizing error
Numerical Results: (N=119) Distribution of G Computed/G Actual as Histogrammean=1.0389, std. dev.=0.158
Numerical Results: Using Global Parameters The Expendables (2010)
Numerical Results: Using Global Parameters Taken (2009)
Numerical Results: Using Global Parameters The Love Guru (2008)
Numerical Results: Using Global Parameters Spider-Man 3 (2007)
Numerical Results: Using Global Parameters Open Season (2006)
Numerical Results: Using Chosen Parameters The Expendables (2010)
Numerical Results: Using Chosen Parameters Open Season (2006)
Future Work “The Holy Grail”: Predict the opening weekend gross before the movie is released The sequel problem: predict the gross of a sequel based on the parent’s characteristics
The Sequel Problem • Considered a subset of the a priori prediction problem with (possibly) more known information • Main assumption is opening weekend revenue, A0, must depend on awareness of film (which probably depends on marketing, M)
Conclusions • Predicting the final accumulated gross of any given movie before it is released is a hard problem • The original EBM should probably be modified to be less movie-specific and the modified EBM changed to be more movie-specific
Acknowledgements • Joint work with Occidental College students Jacob Ortega-Gingrich ’13 and Rohan Shah ’07 • Many thanks to David Edwards and the staff and faculty of University of Delaware