{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2023:BSGZQXPXAZWDAEG5DP4URQQ6AT","short_pith_number":"pith:BSGZQXPX","canonical_record":{"source":{"id":"2311.02299","kind":"arxiv","version":5},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"econ.EM","submitted_at":"2023-11-04T02:03:48Z","cross_cats_sorted":["stat.ME"],"title_canon_sha256":"1c2d736f7995e47cb1b2999cb278f2ab5104851ff913fd71ac6d8cf58d8549f9","abstract_canon_sha256":"e487b6ae81b83f4189e06d53b9ae86ec7c8583279895676ceb0061dc2b4f8f53"},"schema_version":"1.0"},"canonical_sha256":"0c8d985df7066c3010dd1bf948c21e04f5d33846372841f915ab8e0adfc38d1d","source":{"kind":"arxiv","id":"2311.02299","version":5},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2311.02299","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"arxiv_version","alias_value":"2311.02299v5","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2311.02299","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"pith_short_12","alias_value":"BSGZQXPXAZWD","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"BSGZQXPXAZWDAEG5","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"BSGZQXPX","created_at":"2026-05-18T12:33:33Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2023:BSGZQXPXAZWDAEG5DP4URQQ6AT","target":"record","payload":{"canonical_record":{"source":{"id":"2311.02299","kind":"arxiv","version":5},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"econ.EM","submitted_at":"2023-11-04T02:03:48Z","cross_cats_sorted":["stat.ME"],"title_canon_sha256":"1c2d736f7995e47cb1b2999cb278f2ab5104851ff913fd71ac6d8cf58d8549f9","abstract_canon_sha256":"e487b6ae81b83f4189e06d53b9ae86ec7c8583279895676ceb0061dc2b4f8f53"},"schema_version":"1.0"},"canonical_sha256":"0c8d985df7066c3010dd1bf948c21e04f5d33846372841f915ab8e0adfc38d1d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:44:39.780618Z","signature_b64":"yGqec9Ump688NLUND1GH/+YDdZWXVcDIwRkOfl6GvHHrLJPx+5VlDHubW5lAcvEuwV2Kw2gU0oac5XokjTktAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0c8d985df7066c3010dd1bf948c21e04f5d33846372841f915ab8e0adfc38d1d","last_reissued_at":"2026-05-18T02:44:39.779943Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:44:39.779943Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2311.02299","source_version":5,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:44:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MKFE2cDvAJYoXBzXebu0tSUnfhzdO8wtbBk1KVV5sYTDPt1/Nf5fPETE1+azlySItV+Kidbl9pXAQgVR6LokDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T00:51:29.835899Z"},"content_sha256":"903b02246765981b32f59e8b0a08652867228cc9ae3d51615eb0a2ccc8107dd2","schema_version":"1.0","event_id":"sha256:903b02246765981b32f59e8b0a08652867228cc9ae3d51615eb0a2ccc8107dd2"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2023:BSGZQXPXAZWDAEG5DP4URQQ6AT","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Fragility of Sparsity","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["stat.ME"],"primary_cat":"econ.EM","authors_text":"Michal Koles\\'ar, Sebastian T. Roelsgaard, Ulrich K. M\\\"uller","submitted_at":"2023-11-04T02:03:48Z","abstract_excerpt":"We show, using three empirical applications, that linear regression estimates predicated on the assumption of sparsity are fragile in two ways. First, we document that different choices of the regressor matrix which do not impact ordinary least squares (OLS) estimates, such as the choice of baseline category with categorical controls, can move sparsity-based estimates by two standard errors or more. Second, we develop two tests of the sparsity assumption by comparing sparsity-based estimators with OLS. The tests tend to reject the sparsity assumption in all three applications. Unless the numbe"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2311.02299","kind":"arxiv","version":5},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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":"2026-05-18T02:44:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"B8KEJjW5RtWOkK5smdrxaXuXJV2H9qZbD3TzEu5cNgYFYdpYktpCHikgoGLFcuexNOtRyx2Kda1F1MtptyH9Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T00:51:29.836231Z"},"content_sha256":"dd9c0cd09ed163b139286813189a6f207d919b1f219b102685ccc30b38b3f037","schema_version":"1.0","event_id":"sha256:dd9c0cd09ed163b139286813189a6f207d919b1f219b102685ccc30b38b3f037"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/bundle.json","state_url":"https://pith.science/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/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":"2026-06-27T00:51:29Z","links":{"resolver":"https://pith.science/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT","bundle":"https://pith.science/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/bundle.json","state":"https://pith.science/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/state.json","well_known_bundle":"https://pith.science/.well-known/pith/BSGZQXPXAZWDAEG5DP4URQQ6AT/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2023:BSGZQXPXAZWDAEG5DP4URQQ6AT","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":"e487b6ae81b83f4189e06d53b9ae86ec7c8583279895676ceb0061dc2b4f8f53","cross_cats_sorted":["stat.ME"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"econ.EM","submitted_at":"2023-11-04T02:03:48Z","title_canon_sha256":"1c2d736f7995e47cb1b2999cb278f2ab5104851ff913fd71ac6d8cf58d8549f9"},"schema_version":"1.0","source":{"id":"2311.02299","kind":"arxiv","version":5}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2311.02299","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"arxiv_version","alias_value":"2311.02299v5","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2311.02299","created_at":"2026-05-18T02:44:39Z"},{"alias_kind":"pith_short_12","alias_value":"BSGZQXPXAZWD","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"BSGZQXPXAZWDAEG5","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"BSGZQXPX","created_at":"2026-05-18T12:33:33Z"}],"graph_snapshots":[{"event_id":"sha256:dd9c0cd09ed163b139286813189a6f207d919b1f219b102685ccc30b38b3f037","target":"graph","created_at":"2026-05-18T02:44:39Z","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"},"paper":{"abstract_excerpt":"We show, using three empirical applications, that linear regression estimates predicated on the assumption of sparsity are fragile in two ways. First, we document that different choices of the regressor matrix which do not impact ordinary least squares (OLS) estimates, such as the choice of baseline category with categorical controls, can move sparsity-based estimates by two standard errors or more. Second, we develop two tests of the sparsity assumption by comparing sparsity-based estimators with OLS. The tests tend to reject the sparsity assumption in all three applications. Unless the numbe","authors_text":"Michal Koles\\'ar, Sebastian T. Roelsgaard, Ulrich K. M\\\"uller","cross_cats":["stat.ME"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"econ.EM","submitted_at":"2023-11-04T02:03:48Z","title":"The Fragility of Sparsity"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2311.02299","kind":"arxiv","version":5},"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":"sha256:903b02246765981b32f59e8b0a08652867228cc9ae3d51615eb0a2ccc8107dd2","target":"record","created_at":"2026-05-18T02:44:39Z","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":"e487b6ae81b83f4189e06d53b9ae86ec7c8583279895676ceb0061dc2b4f8f53","cross_cats_sorted":["stat.ME"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"econ.EM","submitted_at":"2023-11-04T02:03:48Z","title_canon_sha256":"1c2d736f7995e47cb1b2999cb278f2ab5104851ff913fd71ac6d8cf58d8549f9"},"schema_version":"1.0","source":{"id":"2311.02299","kind":"arxiv","version":5}},"canonical_sha256":"0c8d985df7066c3010dd1bf948c21e04f5d33846372841f915ab8e0adfc38d1d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0c8d985df7066c3010dd1bf948c21e04f5d33846372841f915ab8e0adfc38d1d","first_computed_at":"2026-05-18T02:44:39.779943Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:44:39.779943Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"yGqec9Ump688NLUND1GH/+YDdZWXVcDIwRkOfl6GvHHrLJPx+5VlDHubW5lAcvEuwV2Kw2gU0oac5XokjTktAw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:44:39.780618Z","signed_message":"canonical_sha256_bytes"},"source_id":"2311.02299","source_kind":"arxiv","source_version":5}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:903b02246765981b32f59e8b0a08652867228cc9ae3d51615eb0a2ccc8107dd2","sha256:dd9c0cd09ed163b139286813189a6f207d919b1f219b102685ccc30b38b3f037"],"state_sha256":"e7e3fc6ab6211ef007de6627eb5bdd43f686bf7e725917834a05c1a6e839356d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"pt0Q7YvKhfm/jP1Rq7tEXTBAJvWf5blJ8jvb0XL0hmBIpuWwzvSCkNP/0EEzJMrAShuveHYyFQst9R6qXm5PAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-27T00:51:29.838015Z","bundle_sha256":"b61d93bca16f5b86836fdbe4d3c2857b821d26f0fc4519a0474298e15dd18bc2"}}