{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:MYCLVQ42RXYWWTJVGRYNLEPPTC","short_pith_number":"pith:MYCLVQ42","canonical_record":{"source":{"id":"2005.02502","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2020-05-05T21:15:43Z","cross_cats_sorted":[],"title_canon_sha256":"bde7f859385bdc99f3ac4660a19cf1435be24584d9b42f5f25c91a7c6bfe4417","abstract_canon_sha256":"1a42c9978a2f4eb8a1507539a8bdcac69c61f7587eab190613d719ec20e7616f"},"schema_version":"1.0"},"canonical_sha256":"6604bac39a8df16b4d353470d591ef98b53b198ed421fe9874b6a637023a3bd2","source":{"kind":"arxiv","id":"2005.02502","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2005.02502","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"arxiv_version","alias_value":"2005.02502v1","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2005.02502","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_12","alias_value":"MYCLVQ42RXYW","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_16","alias_value":"MYCLVQ42RXYWWTJV","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_8","alias_value":"MYCLVQ42","created_at":"2026-07-05T01:00:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:MYCLVQ42RXYWWTJVGRYNLEPPTC","target":"record","payload":{"canonical_record":{"source":{"id":"2005.02502","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2020-05-05T21:15:43Z","cross_cats_sorted":[],"title_canon_sha256":"bde7f859385bdc99f3ac4660a19cf1435be24584d9b42f5f25c91a7c6bfe4417","abstract_canon_sha256":"1a42c9978a2f4eb8a1507539a8bdcac69c61f7587eab190613d719ec20e7616f"},"schema_version":"1.0"},"canonical_sha256":"6604bac39a8df16b4d353470d591ef98b53b198ed421fe9874b6a637023a3bd2","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:00:52.838894Z","signature_b64":"C9LDMywtYStNw6Rmp/LnkHUAztlMQCd4CZJvRihIF7TqTCML4nzS4Mhs/9E8XZBgpXuP5anFP1hYz8HMoDa1Ag==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6604bac39a8df16b4d353470d591ef98b53b198ed421fe9874b6a637023a3bd2","last_reissued_at":"2026-07-05T01:00:52.838400Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:00:52.838400Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2005.02502","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:00:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6/YpGFIVHCUYRh8/txW+FlOHTxu43t6EaNnkM9qtOC3xZSdwfWYxvBCWnezaveVK8H51eq6NW+Ncy2HnmCxFDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-09T01:48:29.036806Z"},"content_sha256":"1f9d6d14ac1b96737e773ebdc362d3b8ffa76c410bf3dfdb1ab43042506fc179","schema_version":"1.0","event_id":"sha256:1f9d6d14ac1b96737e773ebdc362d3b8ffa76c410bf3dfdb1ab43042506fc179"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:MYCLVQ42RXYWWTJVGRYNLEPPTC","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Lasso-OLS Hybrid Approach to Covariate Selection and Average Treatment Effect Estimation for Clustered RCTs Using Design-Based Methods","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"stat.ME","authors_text":"Peter Z. Schochet","submitted_at":"2020-05-05T21:15:43Z","abstract_excerpt":"Statistical power is often a concern for clustered RCTs due to variance inflation from design effects and the high cost of adding study clusters (such as hospitals, schools, or communities). While covariate pre-specification is the preferred approach for improving power to estimate regression-adjusted average treatment effects (ATEs), further precision gains can be achieved through covariate selection once primary outcomes have been collected. This article uses design-based methods underlying clustered RCTs to develop a Lasso-OLS hybrid procedure for the post-hoc selection of covariates and AT"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2005.02502","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2005.02502/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:00:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tAJDEx9oh8d0R1r8SraiwIwgAhn/WNxJ7gl8aYtzM9AIHiQsuvE5n02sslFy3ehnnVefY5T5/G/C9IU0rH9hDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-09T01:48:29.037170Z"},"content_sha256":"64f9c86a08a8110d5696daccb328ef6f932931b389082f8c3598cfbe29145c64","schema_version":"1.0","event_id":"sha256:64f9c86a08a8110d5696daccb328ef6f932931b389082f8c3598cfbe29145c64"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/bundle.json","state_url":"https://pith.science/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-09T01:48:29Z","links":{"resolver":"https://pith.science/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC","bundle":"https://pith.science/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/bundle.json","state":"https://pith.science/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MYCLVQ42RXYWWTJVGRYNLEPPTC/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:MYCLVQ42RXYWWTJVGRYNLEPPTC","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"1a42c9978a2f4eb8a1507539a8bdcac69c61f7587eab190613d719ec20e7616f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2020-05-05T21:15:43Z","title_canon_sha256":"bde7f859385bdc99f3ac4660a19cf1435be24584d9b42f5f25c91a7c6bfe4417"},"schema_version":"1.0","source":{"id":"2005.02502","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2005.02502","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"arxiv_version","alias_value":"2005.02502v1","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2005.02502","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_12","alias_value":"MYCLVQ42RXYW","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_16","alias_value":"MYCLVQ42RXYWWTJV","created_at":"2026-07-05T01:00:52Z"},{"alias_kind":"pith_short_8","alias_value":"MYCLVQ42","created_at":"2026-07-05T01:00:52Z"}],"graph_snapshots":[{"event_id":"sha256:64f9c86a08a8110d5696daccb328ef6f932931b389082f8c3598cfbe29145c64","target":"graph","created_at":"2026-07-05T01:00:52Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2005.02502/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Statistical power is often a concern for clustered RCTs due to variance inflation from design effects and the high cost of adding study clusters (such as hospitals, schools, or communities). While covariate pre-specification is the preferred approach for improving power to estimate regression-adjusted average treatment effects (ATEs), further precision gains can be achieved through covariate selection once primary outcomes have been collected. This article uses design-based methods underlying clustered RCTs to develop a Lasso-OLS hybrid procedure for the post-hoc selection of covariates and AT","authors_text":"Peter Z. Schochet","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2020-05-05T21:15:43Z","title":"A Lasso-OLS Hybrid Approach to Covariate Selection and Average Treatment Effect Estimation for Clustered RCTs Using Design-Based Methods"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2005.02502","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:1f9d6d14ac1b96737e773ebdc362d3b8ffa76c410bf3dfdb1ab43042506fc179","target":"record","created_at":"2026-07-05T01:00:52Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"1a42c9978a2f4eb8a1507539a8bdcac69c61f7587eab190613d719ec20e7616f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ME","submitted_at":"2020-05-05T21:15:43Z","title_canon_sha256":"bde7f859385bdc99f3ac4660a19cf1435be24584d9b42f5f25c91a7c6bfe4417"},"schema_version":"1.0","source":{"id":"2005.02502","kind":"arxiv","version":1}},"canonical_sha256":"6604bac39a8df16b4d353470d591ef98b53b198ed421fe9874b6a637023a3bd2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6604bac39a8df16b4d353470d591ef98b53b198ed421fe9874b6a637023a3bd2","first_computed_at":"2026-07-05T01:00:52.838400Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:00:52.838400Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"C9LDMywtYStNw6Rmp/LnkHUAztlMQCd4CZJvRihIF7TqTCML4nzS4Mhs/9E8XZBgpXuP5anFP1hYz8HMoDa1Ag==","signature_status":"signed_v1","signed_at":"2026-07-05T01:00:52.838894Z","signed_message":"canonical_sha256_bytes"},"source_id":"2005.02502","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1f9d6d14ac1b96737e773ebdc362d3b8ffa76c410bf3dfdb1ab43042506fc179","sha256:64f9c86a08a8110d5696daccb328ef6f932931b389082f8c3598cfbe29145c64"],"state_sha256":"04eb493d225f16c573931d3c2d43376ede75396d10190b3d36133e579b591d92"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"obIDkkWYHv/pcyHuJH8hKPMXcqPpmZySfH51uPD9G2MWODQNDR/c1Ozw2tWOw1gYu1QEnIU7oox583NrHNsxDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-09T01:48:29.039061Z","bundle_sha256":"fb5131fe18edbaf17e6ee899b08bbaadf3352cfcaf29364d1d5908db22568f9e"}}