<table><caption>TABLE (A7) Social Motives and Cooperation on Wikipedia: controlling for article controversiality</caption><thead><tr><th rowspan="2"></th><th colspan="2">(1)</th><th colspan="2">(2)</th><th colspan="2">(3)</th><th colspan="2">(4)</th><th colspan="2">(5)</th><th colspan="2">(6)</th><th colspan="2">(7)</th><th colspan="2">(8)</th></tr><tr><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Avg(log persist.)<br>Quality</th><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Avg(log persist.)<br>Quality</th><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Avg(log persist.)<br>Quality</th><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Avg(log persist.)<br>Quality</th></tr></thead><tbody><tr><td>Reciprocator</td><td>0.433**<br>(0.205)</td><td>0.595*<br>(0.315)</td><td>-0.0444*<br>(0.0246)</td><td>-0.00777<br>(0.0699)</td><td>0.778***<br>(0.294)</td><td>0.956**<br>(0.480)</td><td>-0.0540<br>(0.0433)</td><td>-0.0417<br>(0.115)</td><td>-0.955**<br>(0.378)</td><td>-1.117**<br>(0.560)</td><td>0.0167<br>(0.0524)</td><td>0.0634<br>(0.143)</td><td>0.575*<br>(0.333)</td><td>0.981**<br>(0.485)</td><td>-0.0437<br>(0.0371)</td><td>-0.000874<br>(0.219)</td></tr><tr><td>Reciprocator × Superstar</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Altruist</td><td>5.835***<br>(0.387)</td><td>8.712***<br>(0.560)</td><td>0.00215<br>(0.0413)</td><td>-0.503***<br>(0.134)</td><td>8.482***<br>(0.564)</td><td>13.26***<br>(0.900)</td><td>0.0192<br>(0.0828)</td><td>-0.345<br>(0.233)</td><td>-0.0896<br>(0.533)</td><td>-0.121<br>(0.793)</td><td>-0.185*<br>(0.0945)</td><td>-0.199<br>(0.252)</td><td>0.575*<br>(0.333)</td><td>0.981**<br>(0.485)</td><td>-0.0437<br>(0.0371)</td><td>-0.000874<br>(0.219)</td></tr><tr><td>Altruist × Superstar</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Signaler (Userpage)</td><td>5.835***<br>(0.387)</td><td>8.712***<br>(0.560)</td><td>0.00215<br>(0.0413)</td><td>-0.503***<br>(0.134)</td><td>8.482***<br>(0.564)</td><td>13.26***<br>(0.900)</td><td>0.0192<br>(0.0828)</td><td>-0.345<br>(0.233)</td><td>-6.758***<br>(0.722)</td><td>-11.11***<br>(1.067)</td><td>-0.0233<br>(0.0940)</td><td>-0.0989<br>(0.276)</td><td>5.835***<br>(0.387)</td><td>8.712***<br>(0.560)</td><td>0.00215<br>(0.0413)</td><td>-0.000874<br>(0.219)</td></tr><tr><td>Signaler (Userpage) × Superstar</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Superstar</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Age</td><td>0.0316***<br>(0.00837)</td><td>0.0388***<br>(0.0125)</td><td>-0.00356***<br>(0.000811)</td><td>-0.00311<br>(0.00297)</td><td>0.0296***<br>(0.00752)</td><td>0.0364***<br>(0.0110)</td><td>-0.00352***<br>(0.000797)</td><td>-0.00282<br>(0.00296)</td><td>-1.203**<br>(0.516)</td><td>-1.018***<br>(0.260)</td><td>0.0106<br>(0.0435)</td><td>0.0289<br>(0.120)</td><td>0.0265<br>(0.0608)</td><td>0.102<br>(0.0957)</td><td>-0.0120<br>(0.00839)</td><td>-0.000132<br>(0.0241)</td></tr><tr><td>Female</td><td>-0.860***<br>(0.310)</td><td>-1.203**<br>(0.516)</td><td>0.0124<br>(0.0423)</td><td>0.0213<br>(0.118)</td><td>-1.018***<br>(0.260)</td><td>-1.454***<br>(0.434)</td><td>0.0106<br>(0.0435)</td><td>0.0289<br>(0.120)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>-0.0115<br>(0.0664)</td><td>0.00715<br>(0.00533)</td><td>0.000617<br>(0.0492)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>0.0126<br>(0.0166)</td></tr><tr><td>Degree level</td><td>0.0265<br>(0.0608)</td><td>0.102<br>(0.0957)</td><td>-0.0120<br>(0.00839)</td><td>0.0596**<br>(0.0241)</td><td>0.000132<br>(0.0554)</td><td>0.0573<br>(0.0876)</td><td>-0.0130<br>(0.00842)</td><td>0.0573**<br>(0.0242)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>0.00267<br>(0.0425)</td><td>0.00715<br>(0.00533)</td><td>0.0130<br>(0.0166)</td><td>-0.0875**<br>(0.0399)</td><td>-0.108*<br>(0.0619)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td></tr><tr><td>Salary level</td><td>-0.000617<br>(0.0492)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>0.0126<br>(0.0166)</td><td>0.00267<br>(0.0425)</td><td>-0.0115<br>(0.0664)</td><td>0.00715<br>(0.00533)</td><td>0.0130<br>(0.0166)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>0.00267<br>(0.0425)</td><td>0.00715<br>(0.00533)</td><td>0.0130<br>(0.0166)</td><td>-0.0875**<br>(0.0399)</td><td>-0.108*<br>(0.0619)</td><td>0.00630<br>(0.00535)</td><td>0.0126<br>(0.0166)</td></tr><tr><td>Risk aversion</td><td>-0.0875**<br>(0.0399)</td><td>-0.108*<br>(0.0619)</td><td>-0.00178<br>(0.00528)</td><td>-0.00938<br>(0.0154)</td><td>-0.0689*<br>(0.0356)</td><td>-0.0760<br>(0.0555)</td><td>-0.00120<br>(0.00525)</td><td>-0.00928<br>(0.0154)</td><td>-0.0179<br>(0.0777)</td><td>0.00630<br>(0.00535)</td><td>-0.00938<br>(0.0154)</td><td>-0.0689*<br>(0.0356)</td><td>-0.00120<br>(0.00525)</td><td>-0.00928<br>(0.0154)</td><td>-0.0875**<br>(0.0399)</td><td>-0.108*<br>(0.0619)</td><td>0.00630<br>(0.00535)</td><td>0.0126<br>(0.0166)</td></tr><tr><td>Nb Barnstars</td><td>0.0720***<br>(0.0190)</td><td>0.0802***<br>(0.0266)</td><td>-0.00319***<br>(0.00115)</td><td>-0.00737<br>(0.00478)</td><td>0.0623***<br>(0.0152)</td><td>0.0700***<br>(0.0200)</td><td>-0.00266**<br>(0.00117)</td><td>-0.00357<br>(0.00450)</td><td>-0.0179<br>(0.0777)</td><td>1.05e-06<br>(1.05e-06)</td><td>8.87e-06***<br>(3.21e-06)</td><td>3.26e-06<br>(8.01e-06)</td><td>2.31e-06<br>(1.07e-05)</td><td>1.08e-06<br>(1.08e-06)</td><td>8.75e-06***<br>(3.24e-06)</td><td>0.348***<br>(0.0819)</td><td>0.766***<br>(0.131)</td><td>-0.0118*<br>(0.00710)</td><td>0.0190<br>(0.0238)</td></tr><tr><td>Size Userpage (in bytes)</td><td>-3.74e-06<br>(9.22e-06)</td><td>-8.71e-06<br>(1.38e-05)</td><td>1.05e-06<br>(1.05e-06)</td><td>8.87e-06***<br>(3.21e-06)</td><td>3.26e-06<br>(8.01e-06)</td><td>2.31e-06<br>(1.07e-05)</td><td>1.08e-06<br>(1.08e-06)</td><td>8.75e-06***<br>(3.24e-06)</td><td>-3.74e-06<br>(9.22e-06)</td><td>-8.71e-06<br>(1.38e-05)</td><td>1.05e-06<br>(1.05e-06)</td><td>8.87e-06***<br>(3.21e-06)</td><td>3.26e-06<br>(8.01e-06)</td><td>2.31e-06<br>(1.07e-05)</td><td>1.08e-06<br>(1.08e-06)</td><td>8.75e-06***<br>(3.24e-06)</td><td>0.348***<br>(0.0819)</td><td>0.766***<br>(0.131)</td><td>-0.0118*<br>(0.00710)</td><td>0.0190<br>(0.0238)</td></tr><tr><td>Ln(edited articles controversiality score)</td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td><td>0.571</td><td>0.567</td><td>0.0527</td><td>0.0426</td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td><td>0.571</td><td>0.567</td><td>0.0527</td><td>0.0426</td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td></tr><tr><td>N</td><td>647</td><td>647</td><td>477</td><td>533</td><td>647</td><td>647</td><td>477</td><td>533</td><td>647</td><td>647</td><td>477</td><td>533</td><td>647</td><td>647</td><td>477</td><td>533</td><td>647</td><td>647</td><td>477</td><td>533</td></tr><tr><td>adj. R<sup>2</sup></td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td><td>0.571</td><td>0.567</td><td>0.0527</td><td>0.0426</td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td><td>0.571</td><td>0.567</td><td>0.0527</td><td>0.0426</td><td>0.470</td><td>0.458</td><td>0.0486</td><td>0.0386</td></tr></tbody></table>

The table presents OLS estimates with robust standard errors in parentheses (constant not reported). ***, ** and * denote statistical significance at the *p* <0.01, *p* <0.05 and *p* <0.1 levels, respectively.
<table><caption>TABLE (A8) Wikipedia's Superstars: controlling for article controversiality</caption><thead><tr><th rowspan="2"></th><th>(1)</th><th>(2)</th><th>(3)</th><th>(4)</th><th>(5)</th><th>(6)</th><th>(7)</th><th>(8)</th></tr><tr><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + nb contrib.)<br>Quantity 1</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Ln(1 + bytes added)<br>Quantity 2</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Prop(rv w/o expl.)<br>Interactions</th><th>Avg(log persist.)<br>Quality</th><th>Avg(log persist.)<br>Quality</th></tr></thead><tbody><tr><td>Reciprocator</td><td>-0.0992<br>(0.225)</td><td>-0.133<br>(0.229)</td><td>-0.0307<br>(0.266)</td><td>-0.0743<br>(0.272)</td><td>-0.0369<br>(0.0292)</td><td>-0.0363<br>(0.0295)</td><td>0.0132<br>(0.0841)</td><td>0.0231<br>(0.0829)</td></tr><tr><td>Altruist</td><td>0.0772<br>(0.323)</td><td>-0.0779<br>(0.312)</td><td>0.292<br>(0.349)</td><td>0.102<br>(0.328)</td><td>-0.0980***<br>(0.0350)</td><td>-0.0990***<br>(0.0357)</td><td>-0.244*<br>(0.132)</td><td>-0.218*<br>(0.130)</td></tr><tr><td>Signaler (User page)</td><td>1.660***<br>(0.428)</td><td></td><td>2.136***<br>(0.522)</td><td></td><td>-0.0204<br>(0.0475)</td><td></td><td>-0.458***<br>(0.156)</td><td></td></tr><tr><td>Signaler (Barnstars)</td><td></td><td>0.704***<br>(0.227)</td><td></td><td>0.957***<br>(0.260)</td><td></td><td>-0.0242<br>(0.0281)</td><td></td><td>-0.322***<br>(0.0858)</td></tr><tr><td>Age</td><td>0.0279***<br>(0.00805)</td><td>0.0304***<br>(0.00838)</td><td>0.0245***<br>(0.00822)</td><td>0.0277***<br>(0.00850)</td><td>-0.00295***<br>(0.000913)</td><td>-0.00297***<br>(0.000914)</td><td>0.0000275<br>(0.00338)</td><td>-0.000736<br>(0.00334)</td></tr><tr><td>Female</td><td>-0.714**<br>(0.351)</td><td>-0.814**<br>(0.375)</td><td>-0.827*<br>(0.501)</td><td>-0.952*<br>(0.535)</td><td>0.00308<br>(0.0407)</td><td>0.00386<br>(0.0409)</td><td>0.00805<br>(0.113)</td><td>0.0286<br>(0.115)</td></tr><tr><td>Degree level</td><td>-0.0214<br>(0.0669)</td><td>-0.0341<br>(0.0656)</td><td>0.0153<br>(0.0781)</td><td>-0.00112<br>(0.0758)</td><td>-0.0101<br>(0.0100)</td><td>-0.00996<br>(0.00997)</td><td>0.0653**<br>(0.0273)</td><td>0.0708***<br>(0.0273)</td></tr><tr><td>Salary level</td><td>-0.0350<br>(0.0481)</td><td>-0.0254<br>(0.0506)</td><td>-0.0287<br>(0.0528)</td><td>-0.0160<br>(0.0554)</td><td>0.00422<br>(0.00606)</td><td>0.00381<br>(0.00604)</td><td>0.00888<br>(0.0192)</td><td>0.00318<br>(0.0196)</td></tr><tr><td>Risk aversion</td><td>0.00214<br>(0.0427)</td><td>0.00813<br>(0.0430)</td><td>0.0257<br>(0.0520)</td><td>0.0329<br>(0.0522)</td><td>0.00280<br>(0.00613)</td><td>0.00296<br>(0.00613)</td><td>0.00677<br>(0.0168)</td><td>0.00667<br>(0.0167)</td></tr><tr><td>Nb Barnstars</td><td>0.0635***<br>(0.0145)</td><td>0.0585***<br>(0.0152)</td><td>0.0727***<br>(0.0185)</td><td>0.0652***<br>(0.0190)</td><td>-0.00300**<br>(0.00118)</td><td>-0.00262**<br>(0.00117)</td><td>-0.00331<br>(0.00444)</td><td>0.000646<br>(0.00431)</td></tr><tr><td>Size Userpage (in bytes)</td><td>-7.78e-08<br>(9.09e-06)</td><td>9.82e-06<br>(8.69e-06)</td><td>-5.21e-06<br>(1.13e-05)</td><td>7.45e-06<br>(1.00e-05)</td><td>1.89e-06*<br>(1.10e-06)</td><td>1.78e-06*<br>(1.07e-06)</td><td>8.27e-06**<br>(3.71e-06)</td><td>5.86e-06*<br>(3.23e-06)</td></tr><tr><td>Ln(edited articles controversiality score)</td><td>-0.234***<br>(0.0846)</td><td>-0.256***<br>(0.0824)</td><td>-0.178*<br>(0.103)</td><td>-0.206**<br>(0.102)</td><td>-0.0201***<br>(0.00734)</td><td>-0.0198***<br>(0.00726)</td><td>0.0567*<br>(0.0295)</td><td>0.0600**<br>(0.0300)</td></tr><tr><td>N</td><td>308</td><td>308</td><td>308</td><td>308</td><td>292</td><td>292</td><td>292</td><td>292</td></tr><tr><td>adj. R<sup>2</sup></td><td>0.225</td><td>0.208</td><td>0.207</td><td>0.190</td><td>0.0590</td><td>0.0608</td><td>0.0538</td><td>0.0741</td></tr></tbody></table>

The table presents OLS estimates with robust standard errors in parentheses (constant not reported). ***, ** and * denote statistical significance at the *p* <0.01, *p* <0.05 and *p* <0.1 levels, respectively.
<figure><img src="image_10.png" /><figcaption>FIGURE (A3) Altruism and Cooperation: Dynamics</figcaption></figure>