{"edition":"california","organization":"Walk San Francisco","organizationId":"ein:47-2000881","boundaryVersion":"US-CA-state-v1","updated":"2026-09-13","model":{"version":"ca-walk-sf-whole-portfolio-conditional-v1","costScope":"Entire100000ordinary recipient gift. Allocation60000physical,15000otherpolicy,15000survivor,10000shared/reserve is judgment; physical allocation includes supporting costs. Public construction resources separately stress-tested; no restricted-donation denominator.","geographicAttribution":"California benefit fraction .98central,.99favorable,.9adverse is judgment. IncludesSF+restCalifornia residents; excludes out-of-state visitors. No automatic statewide policy spillover and no duplication with SF/Bay edition donations.","formula":"qF=sum(k=1..TF)uF*exp(-hazard*(k-.5))/(1+r)^k. qS=sum(k=1..TS)uS/(1+r)^k. V=sum(t=start..start+delay-1)(1+r)^(-t). Qall=p*b*V*(F*eF*qF+S*eS*qS). QCA=gCA*Qall-H_CA. Price10=10*G/QCA forQCA>0. Ctiming=G+p*[K*((1+r)^(-(start-1))-(1+r)^(-(start+delay-1)))+M*V]. Cgross=G+p*K/(1+r)^(start-1)+p*M*V.","counterfactual":"Same physical package implemented later by public agency/coalition baseline. p jointly includes donor replacement and unique influence; no additional arbitrary attribution multiplier. Only acceleration window counts. Existing cameras/capital not newly purchased by gift.","attribution":"Risk share on disjoint package streets, not share of street length. Separate fatal/nonfatal injury categories; reduce intervention priors for transfer/displacement and subtract independent donor harms. No add-on for overlapping survivor distress, physical activity, emissions or other advocates' projects.","uncertainty":"All influence, targeting, effect-transfer, utility, duration, geography and cost inputs are judgments.Observed25fatalities and historicalseverecontext do not establish future package risk. Scenarios illustrate sensitivity, not statistical bounds; no verified project.","nativeOutcomes":"Additional early exposure-years to a physical traffic-calming package; Incremental fatal and severe nonfatal casualties avoided on disjoint streets; Finite survival and nonfatal impairment QALYs amongCalifornia residents.","inputs":[{"name":"G","value":100000,"unit":"USD","basis":"judgment","rationale":"Whole gift normalization, not recommended gift.","sourceIds":[]},{"name":"physical_allocation","value":0.6,"unit":"fraction of whole gift","basis":"judgment","rationale":"60000 physical implementation staff/support;15000otherpolicy,15000survivors,10000shared/reserve; no second .6 multiplier.","sourceIds":["impact"]},{"name":"p","value":0.1,"unit":"joint probability of gift-caused acceleration","basis":"judgment","rationale":"Includes donor replacement, coalition alternatives, agency baseline and failure. Not measured from wins.","sourceIds":["schools","capital"]},{"name":"b","value":0.02,"unit":"share of baseline casualty risk on package streets","basis":"judgment","rationale":"Hypothetical disjoint package; not street-length share or identified target list.","sourceIds":[]},{"name":"F","value":25,"unit":"traffic fatalities per year","basis":"observed","rationale":"2025 context applied as assumed future baseline; not25pedestrian-only deaths.","sourceIds":["fatal"]},{"name":"S","value":550,"unit":"severe nonfatal traffic injuries per year","basis":"judgment","rationale":"Historical approx550severe injuries/year used as constructed nonfatal baseline; reconcile current protocol and fatal overlap before beta.","sourceIds":["severe"]},{"name":"eF","value":0.1,"unit":"fractional fatality reduction","basis":"judgment","rationale":"Conservative transfer for physical package; fatal evidence uncertain and zero plausible.","sourceIds":["causal"]},{"name":"eS","value":0.2,"unit":"fractional severe-injury reduction","basis":"judgment","rationale":"Physical traffic-calming transfer, not signage or advocacy alone.","sourceIds":["causal"]},{"name":"start","value":2,"unit":"year of early exposure","basis":"judgment","rationale":"Package opens at start of year2; outcomes dated yearend.","sourceIds":[]},{"name":"delay","value":2,"unit":"years accelerated","basis":"judgment","rationale":"Onlyyears2–3incremental; no-gift package then catches up.","sourceIds":["capital"]},{"name":"uF","value":0.8,"unit":"future utility","basis":"judgment","rationale":"Not SF casualty-specific measurement.","sourceIds":[]},{"name":"hazard","value":0.02,"unit":"annual competing mortality hazard","basis":"judgment","rationale":"Includes future causes of death over finite horizon.","sourceIds":[]},{"name":"TF","value":30,"unit":"years","basis":"judgment","rationale":"Finite survival benefit, not full lifetime credited without limit.","sourceIds":[]},{"name":"uS","value":0.1,"unit":"utility loss avoided per severe injury year","basis":"judgment","rationale":"Unverified severity mix, not every injury permanent.","sourceIds":[]},{"name":"TS","value":3,"unit":"years","basis":"judgment","rationale":"Finite nonfatal health loss.","sourceIds":[]},{"name":"r","value":0.03,"unit":"annual discount rate","basis":"judgment","rationale":"Separate event delay and subsequent health duration.","sourceIds":[]},{"name":"gCA","value":0.98,"unit":"California share of net benefit","basis":"judgment","rationale":"Residents from SF/restCalifornia;2% outside-state. Not measured residence share. Sensitivity .9–.99 not confidence bounds.","sourceIds":[]},{"name":"K","value":1000000,"unit":"USD capital per package","basis":"judgment","rationale":"Hypothetical current package cost, not a dated bid.","sourceIds":[]},{"name":"M","value":20000,"unit":"annual USD maintenance","basis":"judgment","rationale":"Hypothetical additional maintenance during acceleration.","sourceIds":[]},{"name":"H_CA","value":0,"unit":"California QALYs","basis":"judgment","rationale":"No independent donor harm central; adverse-harm scenario included.","sourceIds":[]}],"scenarios":[{"id":"central","label":"Conditional central","costUSD":100000,"allPopulationQalys":0.22993161313959018,"editionQalys":0.22533298087679837,"assumptions":"{\"p\":0.1,\"b\":0.02,\"F\":25,\"S\":550,\"eF\":0.1,\"eS\":0.2,\"start\":2,\"delay\":2,\"uF\":0.8,\"hazard\":0.02,\"TF\":30,\"uS\":0.1,\"TS\":3,\"gCA\":0.98,\"r\":0.03,\"K\":1000000,\"M\":20000,\"H_CA\":0}"},{"id":"favorable","label":"Favorable joint stress","costUSD":100000,"allPopulationQalys":37.13815494011909,"editionQalys":36.766773390717894,"assumptions":"{\"p\":0.35,\"b\":0.08,\"F\":25,\"S\":550,\"eF\":0.35,\"eS\":0.4,\"start\":2,\"delay\":5,\"uF\":0.85,\"hazard\":0.01,\"TF\":40,\"uS\":0.15,\"TS\":5,\"gCA\":0.99,\"r\":0.03,\"K\":3000000,\"M\":60000,\"H_CA\":0}"},{"id":"adverse","label":"Adverse positive joint stress","costUSD":100000,"allPopulationQalys":0.00009697192709346115,"editionQalys":0.00008727473438411503,"assumptions":"{\"p\":0.01,\"b\":0.005,\"F\":15,\"S\":300,\"eF\":0.02,\"eS\":0.05,\"start\":3,\"delay\":1,\"uF\":0.65,\"hazard\":0.05,\"TF\":15,\"uS\":0.03,\"TS\":1,\"gCA\":0.9,\"r\":0.03,\"K\":300000,\"M\":10000,\"H_CA\":0}"},{"id":"null","label":"No incremental acceleration","costUSD":100000,"allPopulationQalys":0,"editionQalys":0,"assumptions":"Central exceptp=0; funded agency/coalition work happens on same schedule."},{"id":"fatal-null","label":"No fatality effect","costUSD":100000,"allPopulationQalys":0.11560598677400342,"editionQalys":0.11329386703852336,"assumptions":"Central excepteF=0; clinically important sensitivity to imprecise death evidence."},{"id":"harm-stress","label":"Independent harm exceeds modeled benefit","costUSD":100000,"allPopulationQalys":-0.07006838686040981,"editionQalys":-0.07466701912320162,"assumptions":"Central plus0.3CaliforniaQALY independent adverse access/displacement/opportunity harm; hypothetical, not measured."}],"sensitivity":["p=.01or.35alone multiplies central benefit by.1or3.5; do not combine nonindependent donor and coalition multipliers twice.","Central qF12.308049,qS.282861,V1.857738; independently recalculated from finite formulas.","WithgCA=.9or1andotherscentral,priceabout$4.83mor$4.35m; geography less decisive than influence and targetrisk.","Do not import London all-casualty reduction as a precise SF fatal effect; fatal-null case remains.","Central timing resource and gross-forward costs are109288.68784243458and200802.8537777505; opportunity costs/trafficaccess mayadd harms.","Physical engineering model cannot price a signage-only, education-only or already-installed-camera gift."],"missingInputs":["Verified ordinary-gift allocation and costed additional staff/organizing tranche.","Named package's agency-funded baseline opening date and gift-induced change probability.","Current disjoint street exposure, severity definition and California victim residence.","Design-specific net injury effect including traffic displacement and accessibility.","Victim age/utility/survival and nonfatal duration; avoid fatal/severe overlap.","Current engineering capital/maintenance costs and public opportunity costs.","Marginal survivor-support/other-policy outcomes not quantified inpartial health model."]},"sources":[{"id":"program","title":"Current Slow Our Streets campaign","publisher":"Walk San Francisco","url":"https://walksf.org/slow-our-streets/","published":null,"retrieved":"2026-09-13"},{"id":"impact","title":"Current portfolio and financial source index","publisher":"Walk San Francisco","url":"https://walksf.org/about-us/our-impact/","published":null,"retrieved":"2026-09-13"},{"id":"report25","title":"2025 Impact Report, published June2026","publisher":"Walk San Francisco","url":"https://walksf.org/wp-content/uploads/2026/06/walksf-impact-report-2026_digital_v2.pdf","published":null,"retrieved":"2026-09-13"},{"id":"99025","title":"Original FY2024–25 Form990","publisher":"Walk San Francisco Foundation","url":"https://walksf.org/wp-content/uploads/2026/05/wsff-24-25-taxfinal-990.public.pdf","published":null,"retrieved":"2026-09-13"},{"id":"99024","title":"Original FY2023–24 Form990 with prior-year comparative","publisher":"Walk San Francisco Foundation","url":"https://walksf.org/wp-content/uploads/2025/06/walk-san-francisco-2324-form-990.pdf","published":null,"retrieved":"2026-09-13"},{"id":"fatal","title":"2025 traffic fatality count","publisher":"SFMTA","url":"https://www.sfmta.com/press-releases/press-release-san-francisco-traffic-fatalities-drop-nearly-half-2025","published":"2026-01-08","retrieved":"2026-09-13"},{"id":"severe","title":"2024 Community Health Assessment, historical severe-injury context","publisher":"SF Department of Public Health","url":"https://media.api.sf.gov/documents/San_Francisco_Population_Health_CHA_2024_2025-04.cleaned.pdf","published":null,"retrieved":"2026-09-13"},{"id":"causal","title":"Controlled interrupted time series of London20mph zones","publisher":"Grundy et al., BMJ","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2791801/","published":"2009-12-10","retrieved":"2026-09-13"},{"id":"capital","title":"Current planned street-safety capital projects","publisher":"SFMTA","url":"https://www.sfmta.com/blog/investing-san-francisco-streets-together-new-safety-connectivity-and-community-benefit-projects","published":"2026-05-05","retrieved":"2026-09-13"},{"id":"schools","title":"Safe School Connections draft approach, September2026","publisher":"SFMTA","url":"https://www.sfmta.com/ja/node/45746","published":null,"retrieved":"2026-09-13"},{"id":"daylight","title":"Safety Zone program and Community Corners approval","publisher":"SFMTA","url":"https://www.sfmta.com/press-releases/sfmta-gives-daylighted-curbs-new-purpose-safety-zone-initiative","published":"2026-06-17","retrieved":"2026-09-13"},{"id":"99023","title":"Original FY 2022–23 Form 990, including separately netted event costs","publisher":"Walk San Francisco Foundation","url":"https://walksf.org/wp-content/uploads/2025/06/walk-san-francisco-2223-form-990.pdf","published":null,"retrieved":"2026-09-14"}]}