-
Notifications
You must be signed in to change notification settings - Fork 8
Expand file tree
/
Copy pathpaper-preview.html
More file actions
919 lines (866 loc) · 43 KB
/
Copy pathpaper-preview.html
File metadata and controls
919 lines (866 loc) · 43 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>policyengine: A Microsimulation Tool for Tax-Benefit Policy Analysis</title>
<style>
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Lora:ital,wght@0,400;0,600;0,700;1,400&family=JetBrains+Mono:wght@400&display=swap');
:root {
--pe-blue: #2c6496;
--pe-dark: #1a3a5c;
--pe-light: #e8f0f8;
--accent: #2c6496;
--accent-hover: #1a3a5c;
--text: #1e293b;
--text-secondary: #475569;
--bg: #f7f8fa;
--bg-card: #ffffff;
--border: #dfe3ea;
--code-bg: #f1f4f8;
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: 'Lora', 'Charter', Georgia, serif;
font-size: 16.5px;
line-height: 1.78;
color: var(--text);
background: var(--bg);
-webkit-font-smoothing: antialiased;
}
/* ── Header ── */
.paper-header {
background: linear-gradient(135deg, var(--pe-dark) 0%, var(--pe-blue) 100%);
color: white;
padding: 3rem 2rem 2.5rem;
position: relative;
overflow: hidden;
}
.paper-header::before {
content: '';
position: absolute;
top: -40%;
right: -15%;
width: 500px;
height: 500px;
background: radial-gradient(circle, rgba(255,255,255,0.06) 0%, transparent 70%);
pointer-events: none;
}
.header-inner {
max-width: 820px;
margin: 0 auto;
position: relative;
}
.paper-label {
font-family: 'Inter', -apple-system, sans-serif;
font-size: 0.68rem;
font-weight: 600;
text-transform: uppercase;
letter-spacing: 0.14em;
color: rgba(255,255,255,0.5);
margin-bottom: 0.75rem;
}
.paper-title {
font-family: 'Lora', Georgia, serif;
font-size: 2rem;
font-weight: 700;
line-height: 1.25;
margin-bottom: 1.5rem;
letter-spacing: -0.01em;
}
.authors-grid {
display: flex;
flex-wrap: wrap;
gap: 0.4rem 1.5rem;
margin-bottom: 0.5rem;
font-family: 'Inter', -apple-system, sans-serif;
}
.author-name {
font-size: 0.88rem;
font-weight: 500;
}
.author-name .corr {
color: #93c5fd;
font-size: 0.72rem;
vertical-align: super;
}
.author-name .orcid-link {
opacity: 0.5;
margin-left: 2px;
font-size: 0.75rem;
text-decoration: none;
color: white;
}
.author-name .orcid-link:hover { opacity: 0.8; }
.affiliation-line {
font-family: 'Inter', -apple-system, sans-serif;
font-size: 0.78rem;
opacity: 0.55;
font-style: italic;
margin-bottom: 0.25rem;
}
.date-line {
font-family: 'Inter', -apple-system, sans-serif;
font-size: 0.73rem;
opacity: 0.4;
}
.tags-row {
display: flex;
flex-wrap: wrap;
gap: 0.3rem;
margin-top: 1.15rem;
}
.tag {
font-family: 'Inter', -apple-system, sans-serif;
font-size: 0.67rem;
font-weight: 500;
background: rgba(255,255,255,0.08);
border: 1px solid rgba(255,255,255,0.18);
border-radius: 999px;
padding: 0.18rem 0.6rem;
letter-spacing: 0.02em;
}
/* ── Layout ── */
.container {
max-width: 1080px;
margin: 0 auto;
display: grid;
grid-template-columns: 210px 1fr;
gap: 2.5rem;
padding: 2rem 2rem 4rem;
}
/* ── Sidebar ── */
.sidebar {
position: sticky;
top: 1.5rem;
align-self: start;
font-family: 'Inter', -apple-system, sans-serif;
}
.sidebar h2 {
font-size: 0.6rem;
text-transform: uppercase;
letter-spacing: 0.12em;
color: var(--text-secondary);
font-weight: 600;
margin-bottom: 0.6rem;
padding-bottom: 0.45rem;
border-bottom: 1px solid var(--border);
}
.sidebar ul { list-style: none; }
.sidebar li { margin-bottom: 0.15rem; }
.sidebar a {
font-size: 0.77rem;
color: var(--text-secondary);
text-decoration: none;
display: block;
padding: 0.25rem 0.55rem;
border-radius: 4px;
transition: all 0.15s;
line-height: 1.35;
}
.sidebar a:hover {
color: var(--accent);
background: var(--pe-light);
}
/* ── Article ── */
.paper-body {
background: var(--bg-card);
border-radius: 6px;
box-shadow: 0 1px 3px rgba(0,0,0,0.05), 0 0 0 1px rgba(0,0,0,0.03);
padding: 2.25rem 2.5rem;
max-width: 760px;
}
.paper-body h1 {
font-family: 'Lora', Georgia, serif;
font-size: 1.35rem;
font-weight: 700;
color: var(--text);
margin: 2.5rem 0 0.8rem;
padding-bottom: 0.3rem;
border-bottom: 2px solid var(--accent);
}
.paper-body h1:first-child { margin-top: 0; }
.paper-body p { margin-bottom: 0.95rem; }
.paper-body a {
color: var(--accent);
text-decoration: none;
border-bottom: 1px solid rgba(44,100,150,0.25);
transition: border-color 0.15s;
}
.paper-body a:hover { border-bottom-color: var(--accent); }
.paper-body strong {
font-weight: 600;
color: var(--text);
}
.paper-body ul, .paper-body ol {
margin: 0.5rem 0 1.1rem 1.3rem;
}
.paper-body li { margin-bottom: 0.5rem; }
.paper-body li strong { color: var(--accent-hover); }
.paper-body code {
font-family: 'JetBrains Mono', 'SF Mono', monospace;
font-size: 0.84em;
background: var(--code-bg);
color: #6e3a8a;
padding: 0.1em 0.35em;
border-radius: 3px;
border: 1px solid var(--border);
}
.paper-body pre {
background: var(--code-bg);
border: 1px solid var(--border);
border-radius: 5px;
padding: 1rem 1.25rem;
overflow-x: auto;
margin-bottom: 1rem;
line-height: 1.5;
}
.paper-body pre code {
background: none;
border: none;
padding: 0;
font-size: 0.82em;
color: var(--text);
}
/* ── Table ── */
.paper-body table {
width: 100%;
border-collapse: collapse;
margin: 1rem 0 1.25rem;
font-size: 0.88rem;
font-family: 'Inter', -apple-system, sans-serif;
}
.paper-body thead th {
background: var(--pe-light);
font-weight: 600;
text-align: left;
padding: 0.5rem 0.65rem;
border-bottom: 2px solid var(--accent);
font-size: 0.82rem;
}
.paper-body tbody td {
padding: 0.45rem 0.65rem;
border-bottom: 1px solid var(--border);
}
.paper-body tbody tr:last-child td {
border-bottom: none;
}
/* ── Citations ── */
.citation { color: var(--text-secondary); }
#references + div, #refs {
font-size: 0.84rem;
line-height: 1.6;
font-family: 'Inter', -apple-system, sans-serif;
}
.csl-entry {
margin-bottom: 0.7rem;
padding-left: 2em;
text-indent: -2em;
color: var(--text-secondary);
}
.csl-entry a { word-break: break-all; font-size: 0.82em; }
/* ── Footer ── */
.paper-footer {
text-align: center;
padding: 1.25rem;
font-family: 'Inter', -apple-system, sans-serif;
font-size: 0.73rem;
color: var(--text-secondary);
border-top: 1px solid var(--border);
margin-top: 2rem;
}
.paper-footer a { color: var(--accent); text-decoration: none; }
/* ── Responsive ── */
@media (max-width: 768px) {
.container {
grid-template-columns: 1fr;
padding: 1rem;
}
.sidebar {
position: static;
display: flex;
flex-wrap: wrap;
gap: 0.3rem;
padding-bottom: 0.75rem;
border-bottom: 1px solid var(--border);
margin-bottom: 0.5rem;
}
.sidebar h2 { width: 100%; }
.sidebar ul { display: flex; flex-wrap: wrap; gap: 0.2rem; }
.paper-body { padding: 1.25rem; }
.paper-header { padding: 2rem 1rem; }
.paper-title { font-size: 1.5rem; }
}
@media print {
body { background: white; }
.paper-header { background: none !important; color: var(--text); padding: 1rem 0; }
.tag { border-color: var(--border); color: var(--text-secondary); }
.sidebar { display: none; }
.container { grid-template-columns: 1fr; }
.paper-body { box-shadow: none; padding: 0; }
}
</style>
</head>
<body>
<!-- Header -->
<div class="paper-header">
<div class="header-inner">
<div class="paper-label">JOSS Paper Preview</div>
<h1 class="paper-title">policyengine: A Microsimulation Tool for Tax-Benefit Policy Analysis</h1>
<div class="authors-grid">
<span class="author-name">Vahid Ahmadi<sup>1</sup> <span class="corr">*</span> <a class="orcid-link" href="https://orcid.org/0009-0004-1093-6272" title="ORCID">●</a></span>
<span class="author-name">Max Ghenis<sup>1</sup> <a class="orcid-link" href="https://orcid.org/0000-0002-1335-8277" title="ORCID">●</a></span>
<span class="author-name">Nikhil Woodruff<sup>1</sup> <a class="orcid-link" href="https://orcid.org/0009-0009-5004-4910" title="ORCID">●</a></span>
<span class="author-name">Pavel Makarchuk<sup>1</sup> <a class="orcid-link" href="https://orcid.org/0009-0003-4869-7409" title="ORCID">●</a></span>
<span class="author-name">Anthony Volk<sup>1</sup> <a class="orcid-link" href="https://orcid.org/0009-0009-2183-3064" title="ORCID">●</a></span>
</div>
<div class="affiliation-line"><sup>1</sup> PolicyEngine, Washington, DC, United States</div>
<div class="date-line">22 May 2026</div>
<div class="tags-row">
<span class="tag">Python</span>
<span class="tag">microsimulation</span>
<span class="tag">tax</span>
<span class="tag">benefit</span>
<span class="tag">public policy</span>
<span class="tag">economic analysis</span>
</div>
</div>
</div>
<!-- Content -->
<div class="container">
<nav class="sidebar">
<h2>Contents</h2>
<ul>
<li><a href="#summary">Summary</a></li>
<li><a href="#statement-of-need">Statement of Need</a></li>
<li><a href="#state-of-the-field">State of the Field</a></li>
<li><a href="#software-design">Software Design</a></li>
<li><a href="#research-impact-statement">Research Impact</a></li>
<li><a href="#acknowledgements">Acknowledgements</a></li>
<li><a href="#ai-usage-disclosure">AI Disclosure</a></li>
<li><a href="#references">References</a></li>
</ul>
</nav>
<article class="paper-body">
<h1 id="summary">Summary</h1>
<p>The <code>policyengine</code> Python package <span class="citation"
data-cites="policyengine_py">(PolicyEngine Contributors 2026)</span> is
open-source software for analyzing how tax and benefit policies affect
household incomes and government budgets in the US and UK. It gives
analysts a common workflow for running simulations on representative
microdata or custom households and for comparing current law with
proposed reforms. Country-specific rules live in dedicated packages
(<code>policyengine-us</code> and <code>policyengine-uk</code>), while
<code>policyengine</code> provides shared tools for datasets, reforms,
outputs, and reproducible release bundles. The package also powers the
interactive web application at <a
href="https://policyengine.org">policyengine.org</a>.</p>
<h1 id="statement-of-need">Statement of Need</h1>
<p>Tax-benefit microsimulation models are standard tools for evaluating
the distributional impacts of fiscal policy. Governments, think tanks,
and researchers use them to estimate how policy reforms affect household
incomes, poverty rates, and government budgets. In practice, however,
analysts work across separate components: statutory rules,
representative microdata, reform definitions, and distributional outputs
live in different tools and interfaces. Reproducing a
baseline-versus-reform workflow, or carrying the same analysis pattern
from one country model to another, therefore often requires bespoke
scripts and project-specific conventions. Historical replication is
especially difficult when policy rules, analysis tooling, and
representative microdata are versioned independently and the analyst
must reconstruct which combination produced a published estimate.</p>
<p>The <code>policyengine</code> package provides a consistent Python
API for tax-benefit analysis across multiple country models. Users can
supply their own microdata or use companion representative datasets,
then compute the impact of current law or hypothetical reforms,
including parametric changes to existing policy parameters and
structural modifications to the tax-benefit system, on any household or
a national population. The <code>calculate_household_impact</code>
function computes results for a single household, while the
<code>Simulation</code> class runs population-level analysis on
representative survey datasets with calibrated weights. Optional
behavioral-response assumptions, such as labor supply elasticities, are
applied after the static reform. Version-pinned releases reduce the
bookkeeping needed for replication.</p>
<h1 id="state-of-the-field">State of the Field</h1>
<p>Microsimulation, which Orcutt <span class="citation"
data-cites="orcutt1957">(1957)</span> pioneered and Bourguignon and
Spadaro <span class="citation"
data-cites="bourguignon2006">(2006)</span> surveyed for redistribution
analysis, underpins much of modern fiscal policy evaluation. In the US,
TAXSIM <span class="citation" data-cites="taxsim">(Feenberg and Coutts
1993)</span> at the National Bureau of Economic Research provides tax
calculations, while the Congressional Budget Office and Tax Policy
Center maintain microsimulation tax models <span class="citation"
data-cites="cbo2018taxmodel tpc2022taxmodel">(Congressional Budget
Office 2018; Tax Policy Center 2022)</span>. In the UK, the primary
microsimulation models are UKMOD, which the Institute for Social and
Economic Research (ISER) at the University of Essex maintains as part of
the EUROMOD family <span class="citation"
data-cites="sutherland2013euromod euromod_download_2026">(Sutherland and
Figari 2013; EUROMOD 2026)</span>; HM Treasury’s Intra-Governmental Tax
and Benefit Microsimulation model (IGOTM) <span class="citation"
data-cites="hmt2025igotm">(HM Treasury 2025)</span>; and TAXBEN, which
the Institute for Fiscal Studies maintains <span class="citation"
data-cites="waters2017taxben">(Waters 2017)</span>.</p>
<p>OpenFisca <span class="citation" data-cites="openfisca">(OpenFisca
Contributors 2024)</span> initiated the open-source approach to
tax-benefit microsimulation in France. Other open-source efforts include
the Policy Simulation Library, a collection of policy models and
data-preparation routines <span class="citation"
data-cites="psl2026">(Policy Simulation Library 2026)</span>, and The
Budget Lab’s public US tax-model codebases, including Tax-Simulator and
Cost-Recovery-Simulator <span class="citation"
data-cites="budgetlab_taxsim_2024 budgetlab_costrecovery_2025">(The
Budget Lab at Yale 2024, 2025)</span>. The PolicyEngine developers
originally forked the codebase from OpenFisca and built it on the
<code>policyengine-core</code> framework <span class="citation"
data-cites="policyengine_core">(Woodruff et al. 2024)</span>.</p>
<p>Existing tools serve complementary needs — country-specific
microsimulation (TAXSIM, TAXBEN, IGOTM) or simulation infrastructure
without a shared cross-country analyst API
(<code>policyengine-core</code>, OpenFisca) — leaving a gap in the
open-source ecosystem. The <code>policyengine</code> package fills this
gap by adding shared dataset management, a stable baseline-versus-reform
pattern, structured output types for distributional and regional
analysis, and interfaces for downstream dashboards and reports.
Concretely, the package provides reusable outputs such as
<code>Aggregate</code>, <code>ChangeAggregate</code>, and
<code>IntraDecileImpact</code>, together with bundled analyses such as
<code>economic_impact_analysis()</code>. This separation lets
country-model packages focus on statutory rules while shared analysis
methods evolve independently.</p>
<p>Table 1: Comparison of policyengine with selected tax-benefit
microsimulation tools. Entries refer to capabilities documented for
external users at the time of submission.</p>
<table>
<colgroup>
<col style="width: 20%" />
<col style="width: 20%" />
<col style="width: 20%" />
<col style="width: 20%" />
<col style="width: 20%" />
</colgroup>
<thead>
<tr>
<th>Dimension</th>
<th>policyengine</th>
<th>TAXSIM</th>
<th>UKMOD</th>
<th>OpenFisca</th>
</tr>
</thead>
<tbody>
<tr>
<td>Open source</td>
<td>Yes</td>
<td>Partial</td>
<td>Yes</td>
<td>Yes</td>
</tr>
<tr>
<td>Country coverage</td>
<td>US and UK</td>
<td>US</td>
<td>UK</td>
<td>US, UK, and ~10 other jurisdictions</td>
</tr>
<tr>
<td>Tax and benefit analysis</td>
<td>Yes</td>
<td>Tax only</td>
<td>Yes</td>
<td>Yes</td>
</tr>
<tr>
<td>Python-native implementation</td>
<td>Yes</td>
<td>No</td>
<td>No</td>
<td>Yes</td>
</tr>
<tr>
<td>Shared reform and output API across countries</td>
<td>Yes</td>
<td>No</td>
<td>No</td>
<td>Shared core, country-specific parameters</td>
</tr>
</tbody>
</table>
<h1 id="software-design">Software Design</h1>
<p>The PolicyEngine software stack has four components.
<code>policyengine-core</code> provides reusable simulation
abstractions, versioned parameters, and dataset interfaces that country
packages share <span class="citation"
data-cites="policyengine_core">(Woodruff et al. 2024)</span>. The
<code>policyengine-us</code> and <code>policyengine-uk</code> packages
contain statutory logic, variables, and entity structures specific to
each tax-benefit system. The <code>policyengine</code> package is the
analyst-facing component: it defines shared simulation orchestration,
structured output types, and canonical baseline-versus-reform workflows
such as <code>economic_impact_analysis()</code>. Companion data
repositories hold enhanced survey microdata derived from the Current
Population Survey (CPS) <span class="citation"
data-cites="woodruff2024enhanced_cps">(Woodruff and Ghenis 2024)</span>
and Family Resources Survey <span class="citation"
data-cites="frs2020">(Department for Work and Pensions et al.
2021)</span>. The package does not include a macroeconomic model and
does not capture general equilibrium effects.</p>
<p>This architecture reflects two deliberate trade-offs. Keeping country
statutory rules in separate packages, rather than bundling them into a
monolithic tool, lets each country model release independently; the cost
is that <code>policyengine</code> must track and certify compatible
combinations. Modeling reforms statically, with optional post-hoc
behavioral responses, gives fast and deterministic baselines at the
expense of general equilibrium effects, which are better suited to
dedicated macroeconomic models.</p>
<figure>
<img src="architecture.png" style="width:100.0%"
alt="Figure 1: PolicyEngine runtime architecture. Inputs (rules, microdata, and behavioral responses) flow through the simulation pipeline to produce structured outputs." />
<figcaption aria-hidden="true">Figure 1: PolicyEngine runtime
architecture. Inputs (rules, microdata, and behavioral responses) flow
through the simulation pipeline to produce structured
outputs.</figcaption>
</figure>
<p>For reproducibility, the top-level package acts as a certification
boundary across these components. Country data repositories build
immutable microdata artifacts and publish release manifests with
checksums and the country-model version used during data construction.
Bundled country manifests in <code>policyengine</code> then certify the
runtime bundle: the runtime country-model version, the microdata-package
release, the dataset artifact, and the compatibility basis linking that
runtime model to the build-time data provenance. Analysts can request a
dataset such as <code>enhanced_frs_2023_24</code>, while the runtime
resolves it to a specific versioned artifact and records both runtime
and build-time provenance. The same certification record can be emitted
as a TRACE Transparent Research Object declaration <span
class="citation" data-cites="trace_trov">(TRACE Project 2024)</span>, so
the internal bundle and data manifests remain the operational source of
truth while a standardized signed provenance document is available for
external exchange.</p>
<p>At runtime, a simulation combines a country-model version, household
microdata, and an optional reform; country packages can also apply
behavioral responses, such as labor supply elasticities, after the
static policy reform. The <code>policyengine</code> package then
produces reusable outputs for decile changes, program statistics,
poverty, inequality, and regional impacts. Because the runtime exposes
the resolved certified bundle and compatibility basis, results can be
traced to a specific <code>policyengine</code> release, runtime
country-model release, microdata release, versioned dataset artifact,
and build-time country-model version. Population-scale runs operate on
representative survey microdata and can require several gigabytes of
memory; the US enhanced CPS pipeline is the most demanding of the
bundled workloads.</p>
<p>The following household-level example computes a household’s net
income under baseline law and under a reform that doubles the US
single-filer standard deduction (to $32,200 for 2026):</p>
<div class="sourceCode" id="cb1"><pre
class="sourceCode python"><code class="sourceCode python"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="im">import</span> datetime</span>
<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="im">from</span> policyengine.core <span class="im">import</span> Parameter, ParameterValue, Policy</span>
<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a><span class="im">from</span> policyengine.tax_benefit_models.us <span class="im">import</span> (</span>
<span id="cb1-4"><a href="#cb1-4" aria-hidden="true" tabindex="-1"></a> USHouseholdInput, calculate_household_impact, us_latest,</span>
<span id="cb1-5"><a href="#cb1-5" aria-hidden="true" tabindex="-1"></a>)</span>
<span id="cb1-6"><a href="#cb1-6" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb1-7"><a href="#cb1-7" aria-hidden="true" tabindex="-1"></a>param <span class="op">=</span> Parameter(</span>
<span id="cb1-8"><a href="#cb1-8" aria-hidden="true" tabindex="-1"></a> name<span class="op">=</span><span class="st">"gov.irs.deductions.standard.amount.SINGLE"</span>,</span>
<span id="cb1-9"><a href="#cb1-9" aria-hidden="true" tabindex="-1"></a> tax_benefit_model_version<span class="op">=</span>us_latest,</span>
<span id="cb1-10"><a href="#cb1-10" aria-hidden="true" tabindex="-1"></a>)</span>
<span id="cb1-11"><a href="#cb1-11" aria-hidden="true" tabindex="-1"></a>reform <span class="op">=</span> Policy(</span>
<span id="cb1-12"><a href="#cb1-12" aria-hidden="true" tabindex="-1"></a> name<span class="op">=</span><span class="st">"Double standard deduction"</span>,</span>
<span id="cb1-13"><a href="#cb1-13" aria-hidden="true" tabindex="-1"></a> parameter_values<span class="op">=</span>[ParameterValue(</span>
<span id="cb1-14"><a href="#cb1-14" aria-hidden="true" tabindex="-1"></a> parameter<span class="op">=</span>param,</span>
<span id="cb1-15"><a href="#cb1-15" aria-hidden="true" tabindex="-1"></a> start_date<span class="op">=</span>datetime.date(<span class="dv">2026</span>, <span class="dv">1</span>, <span class="dv">1</span>),</span>
<span id="cb1-16"><a href="#cb1-16" aria-hidden="true" tabindex="-1"></a> end_date<span class="op">=</span>datetime.date(<span class="dv">2026</span>, <span class="dv">12</span>, <span class="dv">31</span>),</span>
<span id="cb1-17"><a href="#cb1-17" aria-hidden="true" tabindex="-1"></a> value<span class="op">=</span><span class="dv">32_200</span>,</span>
<span id="cb1-18"><a href="#cb1-18" aria-hidden="true" tabindex="-1"></a> )],</span>
<span id="cb1-19"><a href="#cb1-19" aria-hidden="true" tabindex="-1"></a>)</span>
<span id="cb1-20"><a href="#cb1-20" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb1-21"><a href="#cb1-21" aria-hidden="true" tabindex="-1"></a>household <span class="op">=</span> USHouseholdInput(</span>
<span id="cb1-22"><a href="#cb1-22" aria-hidden="true" tabindex="-1"></a> people<span class="op">=</span>[{<span class="st">"age"</span>: <span class="dv">40</span>, <span class="st">"employment_income"</span>: <span class="dv">50_000</span>,</span>
<span id="cb1-23"><a href="#cb1-23" aria-hidden="true" tabindex="-1"></a> <span class="st">"is_tax_unit_head"</span>: <span class="va">True</span>}],</span>
<span id="cb1-24"><a href="#cb1-24" aria-hidden="true" tabindex="-1"></a> tax_unit<span class="op">=</span>{<span class="st">"filing_status"</span>: <span class="st">"SINGLE"</span>},</span>
<span id="cb1-25"><a href="#cb1-25" aria-hidden="true" tabindex="-1"></a> household<span class="op">=</span>{<span class="st">"state_code_str"</span>: <span class="st">"CA"</span>},</span>
<span id="cb1-26"><a href="#cb1-26" aria-hidden="true" tabindex="-1"></a> year<span class="op">=</span><span class="dv">2026</span>,</span>
<span id="cb1-27"><a href="#cb1-27" aria-hidden="true" tabindex="-1"></a>)</span>
<span id="cb1-28"><a href="#cb1-28" aria-hidden="true" tabindex="-1"></a>baseline <span class="op">=</span> calculate_household_impact(household)</span>
<span id="cb1-29"><a href="#cb1-29" aria-hidden="true" tabindex="-1"></a>reformed <span class="op">=</span> calculate_household_impact(household, policy<span class="op">=</span>reform)</span>
<span id="cb1-30"><a href="#cb1-30" aria-hidden="true" tabindex="-1"></a><span class="co"># The reform increases this household's net income relative to baseline.</span></span></code></pre></div>
<p>The <code>us_latest</code> sentinel resolves to the bundled
<code>policyengine-us</code> version installed alongside
<code>policyengine</code>, so results are stable for a given pinned
environment. This paper describes <code>policyengine</code> version
4.10.0 <span class="citation" data-cites="policyengine_py">(PolicyEngine
Contributors 2026)</span>, and the checked-in UK reproduction script
<code>examples/paper_repro_uk.py</code> documents an executable
population-level workflow using a pinned interpreter
(<code>uv run --python 3.14 --extra uk python examples/paper_repro_uk.py</code>).</p>
<h1 id="research-impact-statement">Research Impact Statement</h1>
<p>PolicyEngine has seen use in government, policy, and research
settings. In the UK, HM Treasury registered PolicyEngine in the
Algorithmic Transparency Recording Standard as a tool under evaluation
by its Personal Tax, Welfare and Pensions team <span class="citation"
data-cites="hmt2024atrs">(HM Treasury 2024)</span>, and co-author Nikhil
Woodruff adapted PolicyEngine during an Innovation Fellowship with the
data science team at 10 Downing Street <span class="citation"
data-cites="no10fellowship2026">(Woodruff 2026)</span>. In the US, the
Joint Economic Committee built an immigration fiscal impact calculator
on top of PolicyEngine’s microsimulation model <span class="citation"
data-cites="jec2026immigration">(Joint Economic Committee, U.S. Congress
2026)</span>.</p>
<p>The package has also been used in external policy analysis and
validation exercises. Under a memorandum of understanding with the
Federal Reserve Bank of Atlanta, PolicyEngine runs three-way comparisons
against TAXSIM and the Atlanta Fed’s Policy Rules Database <span
class="citation" data-cites="atlanta_fed_prd">(Federal Reserve Bank of
Atlanta 2021)</span>. Organizations including the Niskanen Center and
the National Institute of Economic and Social Research have used
PolicyEngine in published distributional analyses <span class="citation"
data-cites="mccabe2024ctc niesr2025living">(McCabe and Sargeant 2024;
Mosley et al. 2025)</span>, and co-author Max Ghenis and Jason DeBacker
presented related methodology work on the Enhanced CPS at the 117th
Annual Conference on Taxation of the National Tax Association <span
class="citation" data-cites="ghenis2024nta">(Ghenis and DeBacker
2024)</span>. Additional examples of public-facing use include research
collaborations and published analyses with the Better Government Lab,
the Beeck Center at Georgetown University, the Institute of Economic
Affairs, and Matt Unrath at the University of Southern California <span
class="citation"
data-cites="pe_bgl beeck2023rac beeck2025ai woodruff2024nic woodruff2025tax pe_usc">(Ghenis
2024b; Kennan et al. 2023, 2025; Woodruff 2024, 2025; Institute for
Research on Poverty 2025)</span>.</p>
<h1 id="acknowledgements">Acknowledgements</h1>
<p>Arnold Ventures <span class="citation"
data-cites="arnold_ventures">(Arnold Ventures 2023)</span>, NEO
Philanthropy <span class="citation"
data-cites="neo_philanthropy">(Ghenis 2024a)</span>, the Gerald Huff
Fund for Humanity, and the National Science Foundation (NSF POSE Phase
I, Award 2518372) <span class="citation" data-cites="nsf_pose">(National
Science Foundation 2025)</span> funded this work in the US. The Nuffield
Foundation has funded the UK work since September 2024 <span
class="citation" data-cites="nuffield2024grant">(Nuffield Foundation
2024)</span>. These funders had no involvement in the design,
development, or content of this software or paper. All authors are
employed by PolicyEngine and may benefit reputationally from the
software’s adoption; this relationship is disclosed here as a potential
conflict of interest.</p>
<p>We thank all PolicyEngine contributors and the OpenFisca community
for the microsimulation framework from which PolicyEngine was forked
<span class="citation" data-cites="openfisca">(OpenFisca Contributors
2024)</span>. We acknowledge the US Census Bureau for providing access
to the Current Population Survey, and the UK Data Service and the
Department for Work and Pensions for providing access to the Family
Resources Survey.</p>
<h1 id="ai-usage-disclosure">AI Usage Disclosure</h1>
<p>The authors used generative AI tools, specifically Claude Opus 4 by
Anthropic <span class="citation" data-cites="claude2026">(Anthropic
2026)</span>, to assist with code refactoring. Human authors reviewed,
edited, and validated all AI-assisted outputs and made all design
decisions regarding software architecture, policy modeling, and
parameter implementation. The authors remain fully responsible for the
accuracy, originality, and correctness of all submitted materials.</p>
<h1 class="unnumbered" id="references">References</h1>
<div id="refs" class="references csl-bib-body hanging-indent"
role="list">
<div id="ref-claude2026" class="csl-entry" role="listitem">
Anthropic. 2026. <em><span>Claude</span></em>. Released. <a
href="https://www.anthropic.com/claude">https://www.anthropic.com/claude</a>.
</div>
<div id="ref-arnold_ventures" class="csl-entry" role="listitem">
Arnold Ventures. 2023. <em>Public Finance Program</em>. <a
href="https://www.arnoldventures.org/work/public-finance">https://www.arnoldventures.org/work/public-finance</a>.
</div>
<div id="ref-bourguignon2006" class="csl-entry" role="listitem">
Bourguignon, François, and Amedeo Spadaro. 2006. <span>“Microsimulation
as a Tool for Evaluating Redistribution Policies.”</span> <em>The
Journal of Economic Inequality</em> 4: 77–106. <a
href="https://doi.org/10.1007/s10888-005-9012-6">https://doi.org/10.1007/s10888-005-9012-6</a>.
</div>
<div id="ref-cbo2018taxmodel" class="csl-entry" role="listitem">
Congressional Budget Office. 2018. <em>An Overview of <span>CBO</span>’s
Microsimulation Tax Model</em>. <a
href="https://www.cbo.gov/system/files/2018-06/54096-taxmodel.pdf">https://www.cbo.gov/system/files/2018-06/54096-taxmodel.pdf</a>.
</div>
<div id="ref-frs2020" class="csl-entry" role="listitem">
Department for Work and Pensions, Office for National Statistics, and
NatCen Social Research. 2021. <em>Family Resources Survey,
2019-2020</em>. UK Data Service. <a
href="https://doi.org/10.5255/UKDA-SN-8802-1">https://doi.org/10.5255/UKDA-SN-8802-1</a>.
</div>
<div id="ref-euromod_download_2026" class="csl-entry" role="listitem">
EUROMOD. 2026. <em>Download</em>. <a
href="https://euromod-web.jrc.ec.europa.eu/download-euromod">https://euromod-web.jrc.ec.europa.eu/download-euromod</a>.
</div>
<div id="ref-atlanta_fed_prd" class="csl-entry" role="listitem">
Federal Reserve Bank of Atlanta. 2021. <em>Policy Rules Database</em>.
<a
href="https://github.com/Research-Division/policy-rules-database">https://github.com/Research-Division/policy-rules-database</a>.
</div>
<div id="ref-taxsim" class="csl-entry" role="listitem">
Feenberg, Daniel R., and Elisabeth Coutts. 1993.
<span>“<span>TAXSIM</span>: A Tool for Calculating Federal and State
Income Tax Liabilities.”</span> <em>National Tax Journal</em> 46 (3):
271–80. <a
href="https://doi.org/10.2307/3325474">https://doi.org/10.2307/3325474</a>.
</div>
<div id="ref-neo_philanthropy" class="csl-entry" role="listitem">
Ghenis, Max. 2024a. <span>“<span>NEO Philanthropy</span> Awards $200,000
Grant to <span>PolicyEngine</span>.”</span> <a
href="https://policyengine.org/us/research/neo-philanthropy">https://policyengine.org/us/research/neo-philanthropy</a>.
</div>
<div id="ref-pe_bgl" class="csl-entry" role="listitem">
Ghenis, Max. 2024b. <span>“<span>PolicyEngine</span> and <span>Better
Government Lab</span> Collaboration.”</span> <a
href="https://www.policyengine.org/us/research/policyengine-better-government-lab-collaboration">https://www.policyengine.org/us/research/policyengine-better-government-lab-collaboration</a>.
</div>
<div id="ref-ghenis2024nta" class="csl-entry" role="listitem">
Ghenis, Max, and Jason DeBacker. 2024. <em>Enhanced <span>Current
Population Survey</span>: Integrating <span>IRS</span> Public Use File
Data Using Quantile Regression Forests</em>. <a
href="https://ntanet.org/2024/07/117th-annual-conference-on-taxation-full/">https://ntanet.org/2024/07/117th-annual-conference-on-taxation-full/</a>.
</div>
<div id="ref-hmt2024atrs" class="csl-entry" role="listitem">
HM Treasury. 2024. <em><span>HMT</span>: <span>PolicyEngine UK</span> –
Algorithmic Transparency Recording Standard</em>. <a
href="https://www.gov.uk/algorithmic-transparency-records/hmt-modelling-policy-engine">https://www.gov.uk/algorithmic-transparency-records/hmt-modelling-policy-engine</a>.
</div>
<div id="ref-hmt2025igotm" class="csl-entry" role="listitem">
HM Treasury. 2025. <em>Impact on Households: Distributional Analysis to
Accompany Spring Statement 2025</em>. <a
href="https://www.gov.uk/government/publications/supporting-documents-for-spring-statement-2025/impact-on-households-distributional-analysis-to-accompany-spring-statement-2025">https://www.gov.uk/government/publications/supporting-documents-for-spring-statement-2025/impact-on-households-distributional-analysis-to-accompany-spring-statement-2025</a>.
</div>
<div id="ref-pe_usc" class="csl-entry" role="listitem">
Institute for Research on Poverty. 2025. <em>2025–2026 <span>IRP</span>
Extramural Large Grants</em>. <a
href="https://www.irp.wisc.edu/2025-2026-irp-extramural-large-grants/">https://www.irp.wisc.edu/2025-2026-irp-extramural-large-grants/</a>.
</div>
<div id="ref-jec2026immigration" class="csl-entry" role="listitem">
Joint Economic Committee, U.S. Congress. 2026. <em>Immigration Fiscal
Impact Calculator</em>. <a
href="https://www.jec.senate.gov/public/index.cfm/republicans/2026/3/immigration-fiscal-impact-calculator">https://www.jec.senate.gov/public/index.cfm/republicans/2026/3/immigration-fiscal-impact-calculator</a>.
</div>
<div id="ref-beeck2025ai" class="csl-entry" role="listitem">
Kennan, Ariel, Alessandra Garcia Guevara, and Jason Goodman. 2025.
<em><span>AI</span>-Powered Rules as Code: Experiments with Public
Benefits Policy</em>. Beeck Center for Social Impact; Innovation,
Georgetown University. <a
href="https://beeckcenter.georgetown.edu/report/ai-powered-rules-as-code-experiments-with-public-benefits-policy/">https://beeckcenter.georgetown.edu/report/ai-powered-rules-as-code-experiments-with-public-benefits-policy/</a>.
</div>
<div id="ref-beeck2023rac" class="csl-entry" role="listitem">
Kennan, Ariel, Lisa Singh, Bianca Dammholz, Keya Sengupta, and Jason Yi.
2023. <em>Exploring Rules Communication: Moving Beyond Static Documents
to Standardized Code for <span>U.S.</span> Public Benefits
Programs</em>. Beeck Center for Social Impact; Innovation, Georgetown
University. <a
href="https://beeckcenter.georgetown.edu/report/exploring-rules-communication-moving-beyond-static-documents-to-standardized-code-for-u-s-public-benefits-programs/">https://beeckcenter.georgetown.edu/report/exploring-rules-communication-moving-beyond-static-documents-to-standardized-code-for-u-s-public-benefits-programs/</a>.
</div>
<div id="ref-mccabe2024ctc" class="csl-entry" role="listitem">
McCabe, Joshua, and Leah Sargeant. 2024. <em>Building a Stronger
Foundation for <span>American</span> Families: Options for <span>Child
Tax Credit</span> Reform</em>. Niskanen Center. <a
href="https://www.niskanencenter.org/building-a-stronger-foundation-for-american-families-options-for-child-tax-credit-reform/">https://www.niskanencenter.org/building-a-stronger-foundation-for-american-families-options-for-child-tax-credit-reform/</a>.
</div>
<div id="ref-niesr2025living" class="csl-entry" role="listitem">
Mosley, Max, Ryan Wattam, and Carol Vincent. 2025. <em><span>UK</span>
Living Standards Review 2025</em>. National Institute of Economic;
Social Research. <a
href="https://niesr.ac.uk/publications/uk-living-standards-review-2025">https://niesr.ac.uk/publications/uk-living-standards-review-2025</a>.
</div>
<div id="ref-nsf_pose" class="csl-entry" role="listitem">
National Science Foundation. 2025. <em><span>POSE</span>: Phase
<span>I</span>: <span>PolicyEngine</span> – Advancing Public Policy
Analysis</em>. <a
href="https://www.nsf.gov/awardsearch/showAward.jsp?AWD_ID=2518372">https://www.nsf.gov/awardsearch/showAward.jsp?AWD_ID=2518372</a>.
</div>
<div id="ref-nuffield2024grant" class="csl-entry" role="listitem">
Nuffield Foundation. 2024. <em>Enhancing, Localising and Democratising
Tax-Benefit Policy Analysis</em>. <a
href="https://www.nuffieldfoundation.org/project/enhancing-localising-and-democratising-tax-benefit-policy-analysis">https://www.nuffieldfoundation.org/project/enhancing-localising-and-democratising-tax-benefit-policy-analysis</a>.
</div>
<div id="ref-openfisca" class="csl-entry" role="listitem">
OpenFisca Contributors. 2024. <em><span>OpenFisca</span>: Open Rules as
Code for Tax-Benefit Systems</em>. Released. <a
href="https://openfisca.org">https://openfisca.org</a>.
</div>
<div id="ref-orcutt1957" class="csl-entry" role="listitem">
Orcutt, Guy H. 1957. <span>“A New Type of Socio-Economic System.”</span>
<em>Review of Economics and Statistics</em> 39 (2): 116–23. <a
href="https://doi.org/10.2307/1928528">https://doi.org/10.2307/1928528</a>.
</div>
<div id="ref-psl2026" class="csl-entry" role="listitem">
Policy Simulation Library. 2026. <em><span>Policy Simulation
Library</span> (<span>PSL</span>)</em>. <a
href="https://pslmodels.org/">https://pslmodels.org/</a>.
</div>
<div id="ref-policyengine_py" class="csl-entry" role="listitem">
PolicyEngine Contributors. 2026. <em><span
class="nocase">policyengine</span></em>. V. 4.10.0. Released. <a
href="https://github.com/PolicyEngine/policyengine.py">https://github.com/PolicyEngine/policyengine.py</a>.
</div>
<div id="ref-sutherland2013euromod" class="csl-entry" role="listitem">
Sutherland, Holly, and Francesco Figari. 2013.
<span>“<span>EUROMOD</span>: The <span>European Union</span> Tax-Benefit
Microsimulation Model.”</span> <em>International Journal of
Microsimulation</em> 6 (1): 4–26. <a
href="https://doi.org/10.34196/ijm.00075">https://doi.org/10.34196/ijm.00075</a>.
</div>
<div id="ref-tpc2022taxmodel" class="csl-entry" role="listitem">
Tax Policy Center. 2022. <em>Brief Description of the Tax Model</em>. <a
href="https://taxpolicycenter.org/resources/brief-description-tax-model">https://taxpolicycenter.org/resources/brief-description-tax-model</a>.
</div>
<div id="ref-budgetlab_taxsim_2024" class="csl-entry" role="listitem">
The Budget Lab at Yale. 2024. <em>Tax Microsimulation at the Budget
Lab</em>. <a
href="https://budgetlab.yale.edu/research/tax-microsimulation-budget-lab">https://budgetlab.yale.edu/research/tax-microsimulation-budget-lab</a>.
</div>
<div id="ref-budgetlab_costrecovery_2025" class="csl-entry"
role="listitem">
The Budget Lab at Yale. 2025. <em>The Budget Lab’s Model for Tax
Depreciation</em>. <a
href="https://budgetlab.yale.edu/research/budget-labs-model-tax-depreciation">https://budgetlab.yale.edu/research/budget-labs-model-tax-depreciation</a>.
</div>
<div id="ref-trace_trov" class="csl-entry" role="listitem">
TRACE Project. 2024. <em><span>TRACE Transparent Research Object
Vocabulary (TROV)</span></em>. <a
href="https://w3id.org/trace/trov/">https://w3id.org/trace/trov/</a>.
</div>
<div id="ref-waters2017taxben" class="csl-entry" role="listitem">
Waters, Tom. 2017. <em>TAXBEN: The IFS Tax and Benefit Microsimulation
Model</em>. The IFS. <a
href="https://ifs.org.uk/publications/taxben-ifs-tax-and-benefit-microsimulation-model">https://ifs.org.uk/publications/taxben-ifs-tax-and-benefit-microsimulation-model</a>.
</div>
<div id="ref-woodruff2024nic" class="csl-entry" role="listitem">
Woodruff, Nikhil. 2024. <em>Raising Employer <span>NIC</span> in the
<span>Autumn Budget</span></em>. Institute of Economic Affairs. <a
href="https://iea.org.uk/publications/raising-employer-nic-in-the-autumn-budget/">https://iea.org.uk/publications/raising-employer-nic-in-the-autumn-budget/</a>.
</div>
<div id="ref-woodruff2025tax" class="csl-entry" role="listitem">
Woodruff, Nikhil. 2025. <em>Impact of Tax Changes 2025–2026</em>.
Institute of Economic Affairs. <a
href="https://iea.org.uk/publications/impact-of-tax-changes-2025-2026/">https://iea.org.uk/publications/impact-of-tax-changes-2025-2026/</a>.
</div>
<div id="ref-no10fellowship2026" class="csl-entry" role="listitem">
Woodruff, Nikhil. 2026. <em>Informing Policy Using
Micro-Simulations</em>. <a
href="https://policyengine.org/ca/research/policyengine-10-downing-street">https://policyengine.org/ca/research/policyengine-10-downing-street</a>.
</div>
<div id="ref-woodruff2024enhanced_cps" class="csl-entry"
role="listitem">
Woodruff, Nikhil, and Max Ghenis. 2024. <span>“Enhancing Survey
Microdata with Administrative Records: A Novel Approach to
Microsimulation Dataset Construction.”</span> <a
href="https://github.com/PolicyEngine/policyengine-us-data/tree/main/paper">https://github.com/PolicyEngine/policyengine-us-data/tree/main/paper</a>.
</div>
<div id="ref-policyengine_core" class="csl-entry" role="listitem">
Woodruff, Nikhil, Max Ghenis, and Anthony Volk. 2024.
<em><span>PolicyEngine Core</span>: A Microsimulation Framework</em>.
Released. <a
href="https://github.com/PolicyEngine/policyengine-core">https://github.com/PolicyEngine/policyengine-core</a>.
</div>
</div>
</article>
<div class="paper-footer">
JOSS Paper Preview — Generated from <code>paper.md</code> • <a href="https://joss.theoj.org">Journal of Open Source Software</a>
</div>
</body>
</html>