Bounds and Identification of Joint Probabilities of Potential Outcomes and Observed Variables under Monotonicity Assumptions
Organizations: Mohamed bin Zayed University of Artificial Intelligence
Abstract
Evaluating joint probabilities of potential outcomes and observed variables, and their linear combinations, is a fundamental challenge in causal inference. This paper addresses the bounding and identification of these probabilities in settings with discrete treatment and discrete ordinal outcome. We propose new families of monotonicity assumptions and formulate the bounding problem as a linear programming problem. We further introduce a new monotonicity assumption specifically to achieve identification. Finally, we present numerical experiments to validate our methods and demonstrate their application using real-world datasets.
Figures & tables
| Research | Treatment Type | Outcome Type | MA | Objective | Identification |
| Pearl (1999) ; Tian and Pearl (2000) | Binary | Binary | PoC | ||
| Mueller and Pearl (2023) | Binary | Binary | PoC | ||
| Zhang et al. (2025) | Binary | Ordinal | PN | ||
| Zhang et al. (2025) | Binary | Ordinal | PN | ||
| Manski (1997) | Discrete | General | ACE | ||
| This paper | Discrete | Ordinal | Assumptions 7 11 |
| Assumption | LB | UB |
|---|---|---|
| (A1) | 0.000 [0.000,0.000] | 0.261 [0.247,0.274] |
| (A2) | 0.064 [0.042,0.089] | 0.261 [0.247,0.274] |
| (A3) | 0.000 [0.000,0.000] | 0.064 [0.042,0.089] |
| (A4) | 0.014 [0.000,0.039] | 0.114 [0.092,0.139] |
| Assumption | Identification | |
| (A5) | 0.064 [0.042,0.089] | |
| Assumption | LB | UB |
|---|---|---|
| (B1) | 0.203 [0.000,0.489] | 0.997 [0.956,1.000] |
| (B2) | 0.293 [0.000,0.561] | 0.997 [0.956,1.000] |
| (B3) | 0.203 [0.000,0.489] | 0.575 [0.192,0.740] |
| (B4) | 0.207 [0.000,0.489] | 0.783 [0.531,1.000] |
| Assumption | Identification | |
| (B5) | 0.575 [0.192,0.740] | |
| Assumption | LB | UB |
|---|---|---|
| (B1) | 0.044 [0.000,0.280] | 1.000 [1.000,1.000] |
| (B2) | 0.044 [0.000,0.280] | 0.251 [0.013,0.612] |
| (B3) | 0.044 [0.000,0.280] | 1.000 [1.000,1.000] |
| (B4) | 0.044 [0.000,0.280] | 0.404 [0.165,0.665] |
| Assumption | Identification | |
| (B5) | 0.251 [0.013,0.612] | |
Appendix figures & tables24 assets
Supplementary material from the paper’s appendix.
Appendix
| 1/40 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 1/40 | 1/40 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 1/40 | 1/40 | 1/40 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 0.011 | 0.010 | 0.042 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 0.045 | 0.059 | 0.069 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 0.017 | 0.041 | 0.047 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 1/20 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 1/20 | 1/20 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Exp. | ||||
|---|---|---|---|---|
| MAs | ||||
| (i) | 3 | 3 | 3 | 3 |
| (ii) | 3 | 3 | 3 | 3 |
| (iii) | 3 | 3 | 3 | 3 |
| (iv) | 3 | 4 | 3 | 3 |
| Exp. | ||||
|---|---|---|---|---|
| MAs | ||||
| (i) | 2 | 3 | 2 | 3 |
| (ii) | 3 | 3 | 3 | 3 |
| (iii) | 3 | 3 | 2 | 2 |
| (iv) | 3 | 2 | 2 | 2 |
| MAs | Bounds (Exp.) | ||||
|---|---|---|---|---|---|
| (i) | LB | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| (i) | UB | 0.224 [0.100,0.452] | 0.265 [0.200,0.340] | 0.274 [0.245,0.304] | 0.275 [0.268,0.284] |
| (ii) | LB | 0.002 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| (ii) | UB | 0.224 [0.100,0.452] | 0.265 [0.200,0.340] | 0.274 [0.245,0.304] | 0.275 [0.268,0.284] |
| (iii) | LB | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| (iii) | UB | 0.163 [0.000,0.400] | 0.167 [0.105,0.235] | 0.166 [0.144,0.186] | 0.167 [0.161,0.175] |
| MAs | Bounds (Obs.) | ||||
|---|---|---|---|---|---|
| (i) | LB | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] |
| (i) | UB | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] |
| (ii) | LB | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| (ii) | UB | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] |
| (iii) | LB | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] | -2.000 [-2.000,-2.000] |
| (iii) | UB | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] | 2.000 [2.000,2.000] |
| MAs | Bounds (Exp.) | ||||
|---|---|---|---|---|---|
| (i) | LB | 0.417 [0.047,0.952] | 0.441 [0.325,0.570] | 0.432 [0.393,0.472] | 0.432 [0.422,0.443] |
| (i) | UB | 2.003 [0.900,3.052] | 2.176 [1.803,2.485] | 2.189 [2.077,2.313] | 2.197 [2.151,2.240] |
| (ii) | LB | 0.417 [0.047,0.952] | 0.441 [0.325,0.570] | 0.432 [0.393,0.472] | 0.432 [0.422,0.443] |
| (ii) | UB | 0.629 [0.048,1.300] | 0.764 [0.539,1.016] | 0.745 [0.659,0.816] | 0.747 [0.725,0.771] |
| (iii) | LB | 0.417 [0.047,0.952] | 0.441 [0.325,0.570] | 0.432 [0.393,0.472] | 0.432 [0.422,0.443] |
| (iii) | UB | 2.003 [0.900,3.052] | 2.176 [1.803,2.485] | 2.189 [2.077,2.313] | 2.197 [2.151,2.240] |
| Bounds (Both) | ||||
|---|---|---|---|---|
| LB ( [ Li and Pearl, 2024 ] ) | 0.056 [0.000,0.300] | 0.003 [0.000,0.025] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| UB ( [ Li and Pearl, 2024 ] ) | 0.426 [0.100,0.700] | 0.501 [0.410,0.570] | 0.517 [0.485,0.549] | 0.514 [0.505,0.526] |
| LB | 0.056 [0.000,0.300] | 0.003 [0.000,0.025] | 0.000 [0.000,0.000] | 0.000 [0.000,0.000] |
| UB | 0.389 [0.100,0.600] | 0.414 [0.305,0.508] | 0.426 [0.387,0.451] | 0.426 [0.411,0.435] |
| Data | LB | UB | |
|---|---|---|---|
| Obs | (All) | 0.000 [0.000, 0.000] | 0.351 [0.326, 0.374] |
| Exp. & Both | 0.00 | 0.000 [0.000, 0.000] | 0.274 [0.250, 0.301] |
| Exp. & Both | 0.70 | 0.000 [0.000, 0.000] | 0.274 [0.250, 0.301] |
| Exp. & Both | 0.75 | 0.000 [0.000, 0.000] | 0.274 [0.250, 0.301] |
| Exp. & Both | 0.80 | 0.000 [0.000, 0.000] | 0.274 [0.250, 0.301] |
| Exp. & Both | 0.85 | 0.000 [0.000, 0.000] | 0.274 [0.250, 0.301] |
| Data | LB | UB | |
|---|---|---|---|
| Obs | (All) | -2.000 [-2.000, -2.000] | 2.000 [2.000, 2.000] |
| Both | 0.00 | -1.509 [-1.850, -1.267] | 2.000 [2.000, 2.000] |
| Both | 0.70 | -1.509 [-1.850, -1.267] | 2.000 [2.000, 2.000] |
| Both | 0.75 | -1.509 [-1.850, -1.267] | 2.000 [2.000, 2.000] |
| Both | 0.80 | -1.509 [-1.850, -1.267] | 2.000 [2.000, 2.000] |
| Both | 0.85 | -1.509 [-1.850, -1.267] | 2.000 [2.000, 2.000] |
| Data | LB | UB | |
|---|---|---|---|
| Exp. | 0.00 | 0.435 [0.392, 0.474] | 2.196 [2.073, 2.339] |
| Exp. | 0.70 | 0.435 [0.392, 0.474] | 2.195 [2.073, 2.331] |
| Exp. | 0.75 | 0.435 [0.392, 0.474] | 2.141 [2.003, 2.272] |
| Exp. | 0.80 | 0.435 [0.392, 0.474] | 2.041 [1.903, 2.172] |
| Exp. | 0.85 | 0.435 [0.392, 0.474] | 1.921 [1.803, 2.024] |
| Exp. | 0.86 | 0.435 [0.392, 0.474] | 1.863 [1.775, 1.952] |
| LB | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.001 [0.000, 0.008] | 0.009 [0.000, 0.033] | 0.033 [0.012, 0.058] | |
| UB | 0.233 [0.212, 0.258] | 0.208 [0.187, 0.233] | 0.183 [0.162, 0.208] | 0.158 [0.137, 0.183] | 0.133 [0.112, 0.158] | |
| LB | 0.000 [0.000, 0.000] | 0.001 [0.000, 0.008] | 0.009 [0.000, 0.033] | 0.033 [0.012, 0.058] | 0.058 [0.037, 0.083] | |
| UB | 0.233 [0.212, 0.258] | 0.208 [0.187, 0.233] | 0.183 [0.162, 0.208] | 0.158 [0.137, 0.183] | 0.133 [0.112, 0.158] | |
| LB | 0.001 [0.000, 0.008] | 0.009 [0.000, 0.033] | 0.033 [0.012, 0.058] | 0.058 [0.037, 0.083] | 0.083 [0.062, 0.108] | |
| LB | -1.929 [-2.000, -1.667] | -1.713 [-1.909, -1.458] | -1.464 [-1.606, -1.250] | -1.214 [-1.303, -1.042] | -0.965 [-1.000, -0.833] | |
| UB | 1.965 [1.833, 2.000] | 1.965 [1.833, 2.000] | 1.965 [1.833, 2.000] | 1.965 [1.833, 2.000] | 1.965 [1.833, 2.000] | |
| LB | -1.498 [-1.819, -1.250] | -1.498 [-1.819, -1.250] | -1.248 [-1.516, -1.042] | -0.998 [-1.213, -0.833] | -0.749 [-0.909, -0.625] | |
| UB | 1.749 [1.625, 1.909] | 1.749 [1.625, 1.909] | 1.749 [1.625, 1.909] | 1.749 [1.625, 1.909] | 1.749 [1.625, 1.909] | |
| LB | -0.998 [-1.213, -0.833] | -0.998 [-1.213, -0.833] | -0.998 [-1.213, -0.833] | -0.749 [-0.909, -0.625] | -0.499 [-0.606, -0.417] | |
| LB | -1.758 [-2.000, -1.436] | -1.556 [-1.835, -1.241] | -1.307 [-1.546, -1.022] | -1.057 [-1.268, -0.795] | -0.808 [-1.000, -0.564] | |
| UB | 1.926 [1.767, 2.000] | 1.926 [1.767, 2.000] | 1.926 [1.767, 2.000] | 1.926 [1.767, 2.000] | 1.917 [1.752, 2.000] | |
| LB | -1.475 [-1.769, -1.248] | -1.461 [-1.769, -1.198] | -1.216 [-1.467, -0.998] | -0.966 [-1.164, -0.788] | -0.716 [-0.862, -0.564] | |
| UB | 1.744 [1.625, 1.909] | 1.744 [1.625, 1.909] | 1.744 [1.625, 1.909] | 1.744 [1.625, 1.909] | 1.727 [1.551, 1.909] | |
| LB | -0.998 [-1.213, -0.833] | -0.998 [-1.213, -0.833] | -0.998 [-1.213, -0.833] | -0.749 [-0.909, -0.625] | -0.499 [-0.606, -0.417] | |
| LB | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | |
| UB | 0.869 [0.842, 0.898] | 0.869 [0.842, 0.898] | 0.869 [0.842, 0.898] | 0.869 [0.842, 0.898] | 0.869 [0.842, 0.898] | |
| LB | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | |
| UB | 0.719 [0.692, 0.748] | 0.719 [0.692, 0.748] | 0.719 [0.692, 0.748] | 0.719 [0.692, 0.748] | 0.719 [0.692, 0.748] | |
| LB | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | 0.269 [0.242, 0.298] | |
| LB | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | |
| UB | 1.200 [1.175, 1.219] | 1.200 [1.175, 1.219] | 1.197 [1.172, 1.218] | 1.175 [1.149, 1.198] | 1.150 [1.124, 1.173] | |
| LB | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | |
| UB | 1.100 [1.075, 1.119] | 1.100 [1.075, 1.119] | 1.097 [1.072, 1.118] | 1.075 [1.049, 1.098] | 1.050 [1.024, 1.073] | |
| LB | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | 0.000 [0.000, 0.000] | |
| 1/21 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 1/21 | 1/21 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| MAs | Data | ||||
|---|---|---|---|---|---|
| (I) | Exp. | 0.142 [0.000,0.353] | 0.145 [0.085,0.225] | 0.142 [0.120,0.166] | 0.143 [0.135,0.150] |
| (II) | Obs. | 0.190 [0.000,0.500] | 0.143 [0.020,0.309] | 0.152 [0.085,0.226] | 0.144 [0.128,0.157] |
| MAs | Data | ||||
|---|---|---|---|---|---|
| (II) | Obs. | 0.431 [0.000,1.000] | 0.332 [0.042,0.700] | 0.321 [0.202,0.465] | 0.334 [0.288,0.382] |
| MAs | Data | ||||
|---|---|---|---|---|---|
| (I) | Exp. | 0.313 [0.000,0.600] | 0.279 [0.200,0.350] | 0.288 [0.264,0.314] | 0.285 [0.278,0.294] |
| (II) | Obs. | 0.395 [0.000,1.000] | 0.303 [0.077,0.561] | 0.285 [0.169,0.388] | 0.282 [0.238,0.319] |