Q: The burst analysis of sales shows that there are LOTS of companies whose sales increased dramatically (even 1000 times) at some point. Is this credible?

A:

I double-checked those companies with unusual sales bursts. Assuming contest data is ok, our burst analysis is honest. The following query result shows those companies with at least 100 times of sales increase AND at least 10 times #employees increase. (sales1 is one's sales in the previous year while sales2 is its sales in the current year.)

 

infovis05=> select * from v_company_sales_employ_bursts_10 where sales_inc_rate >= 100 order by sales_inc_rate desc;

year  company_id  sales1  sales2  sales_inc_rate  employees1  employees2  empl_inc_rate
2000  77213  0.3  1000 3333  3333  55000 17
2001  47898  0.1  177.7 1777  200  2000 10
2002  64363  0.3  320.31 1068  3  2500 833
1999  73981  0.3  260 867  10  2000 200
2002  68512  1.2  1000 833  60  8615 144
1994  65945  1.2  666.6 555  120  10000 83
1999  37810  13.2  6267 475  46  6666 145
1994  61218  9.4  3900 415  75  30000 400
1992  71705  3.3  1365 414  100  6373 64
1999  63996  1.5  610 407  333  3800 11
1993  84772  0.25  100 400  2  600 300
1999  70715  66.6  24713 371  1300  28000 22
1996  1576  0.3  110 367  3  900 300
1991  55173  7.1  2600 366  75  28000 373
1999  20252  2.1  765.8 365  16  4900 306
2002  6144  0.3  100 333  3  80 27
1996  37121  2  666.6 333  15  650 43
1997  32657  15  4500 300  150  19000 127
2002  11209  0.97  289 298  6  1200 200
1994  71058  2.4  701.8 292  15  1139 76
1996  6626  0.23  65 283  2  66 33
2001  61645  6.6  1756.1 266  100  13000 130
2002  50462  10  2501 250  72  10889 151
1995  33503  3.3  700 212  40  2500 62
2003  39730  0.769  139.61 182  6  760 127
1991  9398  1.5  262 175  25  2303 92
1995  55061  4.1  650 159  40  5700 142
2003  1521  0.61  95 156  5  370 74
1995  47803  6.6  1000 152  88  1000 11
2003  18808  3.33  500 150  14  1495 107
2002  35536  5  744.3 149  36  6000 167
1994  25360  0.49  66.6 136  3  600 200
2003  45017  3.724  500 134  28  1500 54
1991  24467  1.2  160 133  15  1500 100
1994  85442  10  1300 130  100  11841 118
1990  60398  0.9  114 127  3  4500 1,500
2003  34019  2.395  300 125  13  1700 131
1992  80485  0.75  93 124  8  1000 125
1996  12177  10  1200 120  60  6500 108
2002  62896  0.134  16.062 120  1  120 120
2001  82381  59  6936.92 118  400  47000 118
1996  11374  0.696  80.656 116  115  1400 12
1997  26471  10.506  1212.2 115  65  7500 115
2003  69991  1.339  150.06 112  10  700 70
1998  87323  0.3  33.3 111  10  550 55
2002  30181  0.469  50 107  2  100 50
1991  5714  0.33  35 106  3  280 93
2003  67190  4.016  420.4 105  30  1400 47
2002  33341  50  5200 104  150  27000 180
2000  12164  0.97  100 103  6  400 67
1998  14969  6.6  666.6 101  35  6666 190
1999  79143  0.25  25 100  14  300 21
2001  7019  2.5  250 100  18  475 26
2001  70547  1  100 100  10  110 11