The Education Production Function Empirical evidence indicates that: increasing school spending has a modest impact on achievement. Urban schools spend more per student than suburban schools yet the achievement gap persists Questions: What is the nature of the relationship between school spending and achievement? What variables determine achievement? Do scores capture educational output?

Hypotheses Result Description 1. x 0 L An increase in population will increase urban extent and urban expansion. 2. x 0 y An increase in household income will increase urban extent and urban expansion. 3. x 0 t An increase in transportation costs will reduce urban extent and limit urban expansion. 4. x 0 rA 5. x 0 H l 6. x 0 7. x 0 f l 8. x 0 w An increase in the opportunity cost of non-urban land will reduce urban extent and limit urban expansion. An increase in the marginal productivity of land in housing production will cause urban expansion. An increase in the share of land available for housing development will increase urban extent and urban expansion. An increase in marginal productivity of land in production of the export good will increase urban extent and urban expansion. An increase in the world price of the export good will increase urban extent and urban expansion.

"Gap Hill Climbing": mathematical analysis 1. To increase gap size, we hill climb the standard deviation of the functional, F (hoping that a "rotation" of d toward a higher StDev would increase the likelihood that gaps would be larger since more dispersion allows for more and/or larger gaps. This is very heuristic but it works. 2. We are more interested in growing the largest gap(s) of interest ( or largest thinning). To do this we could do: F-slices are hyperplanes (assuming F=dotd) so it would makes sense to try to "re-orient" d so that the gap grows. Instead of taking the "improved" p and q to be the means of the entire n-dimensional half-spaces which is cut by the gap (or thinning), take as p and q to be the means of the F-slice (n-1)-dimensional hyperplanes defining the gap or thinning. This is easy since our method produces the pTree mask of each F-slice ordered by increasing F-value (in fact it is the sequence of F-values and the sequence of counts of points that give us those value that we use to find large gaps in the first place.). The d2-gap is much larger than the d1=gap. It is still not the optimal gap though. Would it be better to use a weighted mean (weighted by the distance from the gap - that is weighted by the d-barrel radius (from the center of the gap) on which each point lies?) In this example it seems to make for a larger gap, but what weightings should be used? (e.g., 1/radius2) (zero weighting after the first gap is identical to the previous). Also we really want to identify the Support vector pair of the gap (the pair, one from one side and the other from the other side which are closest together) as p and q (in this case, 9 and a but we were just lucky to draw our vector through them.) We could check the d-barrel radius of just these gap slice pairs and select the closest pair as p and q??? 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 0 2 3 4 5 6 7 8 =p 9 d 2-gap d2 d 1-g ap j d k c e m n r f s o g p h i d1 l q f e d c b a 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 2 3 4 5p 6 7 8 9d 1-g ap d 2-gap a q=b d2 f e d c b a 9 8 7 6 5 4 3 2 1 0 a b d d1 j k qc e q f

"Gap Hill Climbing": mathematical analysis One way to increase the size of the functional gaps is to hill climb the standard deviation of the functional, F (hoping that a "rotation" of d toward a higher STDev would increase the likelihood that gaps would be larger ( more dispersion allows for more and/or larger gaps). This is very general. We are more interested in growing the one particular gap of interest (largest gap or largest thinning). To do this we can do as follows: F-slices are hyperplanes (assuming F=dotd) so it would makes sense to try to "re-orient" d so that the gap grows. Instead of taking the "improved" p and q to be the means of the entire n-dimensional half-spaces which is cut by the gap (or thinning), take as p and q to be the means of the F-slice (n-1)-dimensional hyperplanes defining the gap or thinning. This is easy since our method produces the pTree mask of each F-slice ordered by increasing F-value (in fact it is the sequence of F-values and the sequence of counts of points that give us those value that we use to find large gaps in the first place.). The d2-gap is much larger than the d1=gap. It is still not the optimal gap though. Would it be better to use a weighted mean (weighted by the distance from the gap - that is weighted by the d-barrel radius (from the center of the gap) on which each point lies?) In this example it seems to make for a larger gap, but what weightings should be used? (e.g., 1/radius2) (zero weighting after the first gap is identical to the previous). Also we really want to identify the Support vector pair of the gap (the pair, one from one side and the other from the other side which are closest together) as p and q (in this case, 9 and a but we were just lucky to draw our vector through them.) We could check the d-barrel radius of just these gap slice pairs and select the closest pair as p and q??? 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 0 2 3 4 5 6 7 8 =p 9 d 2-gap d2 d 1-g ap j d k c e m n r f s o g p h i d1 l q f e d c b a 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 2 3 4 5p 6 7 8 9d 1-g ap d 2-gap a q=b d2 f e d c b a 9 8 7 6 5 4 3 2 1 0 a b d d1 j k qc e q f

"Gap Hill Climbing": mathematical analysis One way to increase the size of the functional gaps is to hill climb the standard deviation of the functional, F (hoping that a "rotation" of d toward a higher STDev would increase the likelihood that gaps would be larger ( more dispersion allows for more and/or larger gaps). We can also try to grow one particular gap or thinning using support pairs as follows: F-slices are hyperplanes (assuming F=dotd) so it would makes sense to try to "re-orient" d so that the gap grows. Instead of taking the "improved" p and q to be the means of the entire n-dimensional half-spaces which is cut by the gap (or thinning), take as p and q to be the means of the F-slice (n-1)-dimensional hyperplanes defining the gap or thinning. This is easy since our method produces the pTree mask of each F-slice ordered by increasing F-value (in fact it is the sequence of F-values and the sequence of counts of points that give us those value that we use to find large gaps in the first place.). The d2-gap is much larger than the d1=gap. It is still not the optimal gap though. Would it be better to use a weighted mean (weighted by the distance from the gap - that is weighted by the d-barrel radius (from the center of the gap) on which each point lies?) In this example it seems to make for a larger gap, but what weightings should be used? (e.g., 1/radius2) (zero weighting after the first gap is identical to the previous). Also we really want to identify the Support vector pair of the gap (the pair, one from one side and the other from the other side which are closest together) as p and q (in this case, 9 and a but we were just lucky to draw our vector through them.) We could check the d-barrel radius of just these gap slice pairs and select the closest pair as p and q??? 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 0 2 3 4 5 6 7 8 =p 9 d 2-gap d2 d 1-g ap j d k c e m n r f s o g p h i d1 l q f e d c b a 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 1 2 3 4 5p 6 7 8 9d 1-g ap d 2-gap a q=b d2 f e d c b a 9 8 7 6 5 4 3 2 1 0 a b d d1 j k qc e q f