diff --git a/lectures/util_rand_resp.md b/lectures/util_rand_resp.md index 0afeca4d3..4dbea0c5c 100644 --- a/lectures/util_rand_resp.md +++ b/lectures/util_rand_resp.md @@ -54,7 +54,7 @@ These design probabilities in turn can be used to compute the conditional probab $$ \text{Pr}(A|r)=\frac{\pi_A \text{Pr}(r|A)}{\pi_A \text{Pr}(r|A)+ (1-\pi_A) \text{Pr}(r|A^{'})} -$$ (eq:one) +$$ (eq:util-rand-one) ## Zoo of Concepts @@ -71,13 +71,13 @@ $$ \text{or}&\\ \text{Pr}(A^{'}|r)&>1-\pi_A \end{aligned} -$$ (eq:two) +$$ (eq:util-rand-two) From Bayes's rule: $$ \frac{\text{Pr}(A|r)}{\text{Pr}(A^{'}|r)}\times \frac{(1-\pi_A)}{\pi_A} = \frac{\text{Pr}(r|A)}{\text{Pr}(r|A^{'})} -$$ (eq:three) +$$ (eq:util-rand-three) If this expression is greater (less) than unity, it follows that r is jeopardizing with respect to $A$($A^{'}$). Then, the natural measure of jeopardy will be: @@ -87,7 +87,7 @@ g(r|A)&=\frac{\text{Pr}(r|A)}{\text{Pr}(r|A^{'})}\\ &\text{and}\\ g(r|A^{'})&=\frac{\text{Pr}(r|A^{'})}{\text{Pr}(r|A)} \end{aligned} -$$ (eq:four) +$$ (eq:util-rand-four) Suppose, without loss of generality, that $\text{Pr}(\text{yes}|A)>\text{Pr}(\text{yes}|A^{'})$, then a yes (no) answer is jeopardizing with respect $A$($A^{'}$), that is, @@ -126,7 +126,7 @@ For that reason, Lanke (1976) {cite}`lanke1976degree` argued that ah appropriat $$ \max \left\{ \text{Pr}(A|\text{yes}) , \text{Pr}(A|\text{no}) \right\} -$$ (eq:five) +$$ (eq:util-rand-five-a) Holding this measure constant, he explained under what conditions the smallest variance of the estimate was achieved with the unrelated question model or Warner's (1965) original model. @@ -138,7 +138,7 @@ They measured "private protection" as $$ \frac{1-\max \left\{ \text{Pr}(A|\text{yes}) , \text{Pr}(A|\text{no}) \right\}}{1-\pi_A} -$$ (eq:six) +$$ (eq:util-rand-six) ### 2.4 Greenberg, Kuebler, Abernathy, and Horvitz (1977) @@ -151,13 +151,13 @@ They defined the hazard for an individual in $A$ as the probability that he or s $$ \text{Pr}(\text{yes}|A)\times \text{Pr}(A|\text{yes})+\text{Pr}(\text{no}|A)\times \text{Pr}(A|\text{no}) -$$ (eq:seven-a) +$$ (eq:util-rand-seven-a) Similarly, the hazard for an individual who does not belong to $A$ would be $$ \text{Pr}(\text{yes}|A^{'})\times \text{Pr}(A|\text{yes})+\text{Pr}(\text{no}|A^{'}) \times \text{Pr}(A|\text{no}) -$$ (eq:seven-b) +$$ (eq:util-rand-seven-b) Greenberg et al. (1977) also considered an alternative related measure of hazard that "is likely to be closer to the actual concern felt by a respondent." @@ -165,13 +165,13 @@ The "limited hazard" for an individual in $A$ and $A^{'}$ is $$ \text{Pr}(\text{yes}|A)\times \text{Pr}(A|\text{yes}) -$$ (eq:eight-a) +$$ (eq:util-rand-eight-a) and $$ \text{Pr}(\text{yes}|A^{'})\times \text{Pr}(A|\text{yes}) -$$ (eq:eight-b) +$$ (eq:util-rand-eight-b) This measure is just the first term in $(7)$, i.e., the probability that an individual answers "yes" and is perceived to belong to A. @@ -210,13 +210,13 @@ Then there is an $r_i$ such that $$ \frac{\partial U_i\left(\text{Pr}(A|r_i),\phi_i\right) }{\partial \text{Pr}(A|r_i)} <0, \text{ for } \phi_i \in \left\{\text{truth},\text{lie}\right\} -$$ (eq:nine-a) +$$ (eq:util-rand-nine-a) and $$ U_i\left(\text{Pr}(A|r_i),\text{truth}\right)>U_i\left(\text{Pr}(A|r_i),\text{lie}\right) , \text{ for } \text{Pr}(A|r_i) \in [0,1] -$$ (eq:nine-b) +$$ (eq:util-rand-nine-b) Suppose now that correct answer for individual $i$ is "yes". @@ -224,14 +224,14 @@ Individual $i$ would choose to answer truthfully if $$ U_i\left(\text{Pr}(A|\text{yes}),\text{truth}\right)\geq U_i\left(\text{Pr}(A|\text{no}),\text{lie}\right) -$$ (eq:ten-a) +$$ (eq:util-rand-ten-a) If the correct answer is "no," individual $i$ would volunteer the correct answer only if $$ U_i\left(\text{Pr}(A|\text{no}),\text{truth}\right)\geq U_i\left(\text{Pr}(A|\text{yes}),\text{lie}\right) -$$ (eq:ten-b) +$$ (eq:util-rand-ten-b) Assume that @@ -249,7 +249,7 @@ At equality, constraint $(10.\text{a})$ determines conditional probabilities t $$ U_i\left(\text{Pr}(A|\text{yes}),\text{truth}\right)= U_i\left(\text{Pr}(A|\text{no}),\text{lie}\right) -$$ (eq:eleven) +$$ (eq:util-rand-eleven) Equation $(11)$ defines a "truth border". @@ -257,7 +257,7 @@ Differentiating $(11)$ with respect to the conditional probabilities shows that $$ \frac{\partial \text{Pr}(A|\text{no})}{\partial \text{Pr}(A|\text{yes})}=\frac{\frac{\partial U_i\left(\text{Pr}(A|\text{yes}),\text{truth}\right) }{\partial \text{Pr}(A|\text{yes})}}{\frac{\partial U_i\left(\text{Pr}(A|\text{no}),\text{lie}\right) }{\partial \text{Pr}(A|\text{no})}}>0 -$$ (eq:twelve) +$$ (eq:util-rand-twelve) The source of the positive relationship is: @@ -350,7 +350,7 @@ $$ V(\text{Pr}(A|\text{yes}) , \text{Pr}(A|\text{no})) = &\frac{{\pi_A}^2 (1-\pi_A)^2}{n}\times \frac{1}{\text{Pr}(A|\text{yes})-\pi_A}\times \frac{1}{\pi_A-\text{Pr}(A|\text{no})} \end{aligned} -$$ (eq:thirteen) +$$ (eq:util-rand-thirteen) where the random sample with replacement consists of $n$ individuals. @@ -360,11 +360,11 @@ The following inequalities restrict the shapes of iso-variance curves: $$ \frac{d \text{ Pr}(A|\text{no})}{d\text{ Pr}(A|\text{yes})}\bigg|_{\text{constant variance}}=\frac{\pi_A-\text{Pr}(A|\text{no})}{\text{Pr}(A|\text{yes})-\pi_A}>0 -$$ (eq:fourteen-a) +$$ (eq:util-rand-fourteen-a) $$ \frac{d^2 \text{ Pr}(A|\text{no})}{d\text{ Pr}(A|\text{yes})^2}\bigg|_{\text{constant variance}}=- \frac{2 \left[\pi_A-\text{Pr}(A|\text{no})\right]}{\left[\text{Pr}(A|\text{yes})-\pi_A \right]^2}<0 -$$ (eq:fourteen-b) +$$ (eq:util-rand-fourteen-b) From expression $(13)$ and $(14)$ we can see that: @@ -477,7 +477,7 @@ Lanke (1976) recommends a privacy protection criterion that minimizes: $$ \max \left\{ \text{Pr}(A|\text{yes}) , \text{Pr}(A|\text{no}) \right\} -$$ (eq:five) +$$ (eq:util-rand-five-b) Following Lanke's suggestion, the statistician should find the highest possible $\text{ Pr}(A|\text{yes})$ consistent with truth telling while $\text{ Pr}(A|\text{no})$ is fixed at 0. The variance is then minimized at point $X$ in Figure 3. @@ -615,13 +615,13 @@ Greenberg et al. (1977) defined the hazard for an individual in $A$ as the proba $$ \text{Pr}(\text{yes}|A)\times \text{Pr}(A|\text{yes})+\text{Pr}(\text{no}|A)\times \text{Pr}(A|\text{no}) -$$ (eq:seven-a) +$$ (eq:util-rand-seven-aa) The hazard for an individual who does not belong to $A$ is $$ \text{Pr}(\text{yes}|A^{'})\times \text{Pr}(A|\text{yes})+\text{Pr}(\text{no}|A^{'}) \times \text{Pr}(A|\text{no}) -$$ (eq:seven-a) +$$ (eq:util-rand-seven-bb) They also considered an alternative related measure of hazard that they said "is likely to be closer to the actual concern felt by a respondent." @@ -629,13 +629,13 @@ Their "limited hazard" for an individual in $A$ and $A^{'}$ is $$ \text{Pr}(\text{yes}|A)\times \text{Pr}(A|\text{yes}) -$$ (eq:eight-a) +$$ (eq:util-rand-eight-aa) and $$ \text{Pr}(\text{yes}|A^{'})\times \text{Pr}(A|\text{yes}) -$$ (eq:eight-b) +$$ (eq:util-rand-eight-bb) According to Greenberg et al. (1977), a respondent commits himself or herself to answer truthfully on the basis of a probability in $(7)$ or $(8)$ **before** randomly selecting the question to be answered.