Table 7.  Predictability of Market Advisory Service Performance by Winner and Loser Categories Between Pairs of Overlapping Crop Years, Wheat Net Advisory Price, 1995-1998 Crop Years
              Two-tail  
Year t Year t+1   Winner t+1 Loser t+1 Odds Ratio Z-statistic p-value  
---number of services---
1995 1996 Winner t 5 6 0.69 -0.43 0.67
Loser t 6 5
1996 1997 Winner t 4 5 0.80 -0.24 0.81
Loser t 5 5
1997 1998 Winner t 9 1 81.00 2.95 0.00 ***
Loser t 1 9
1995-1998 Winner t 18 12 2.38 1.65 0.10 *
Total Loser t 12 19        
Note:  The selection strategy consists of ranking services by pricing performance (net advisory price and return result in the same rankings) in the first year of the pair (e.g., t = 1995) and then forming two groups of programs:  "winners" are those services in the top half of the rankings and "losers" are services in the bottom half. Next, the same services are ranked by pricing performance for the second year of the pair (e.g., t+1 = 1996), and again divided into "winners" and "losers."  For a given comparison, advisory services must fall in one of the following categories: winner t-winner t+1, winner t-loser t+1, loser t-winner t+1, loser t-loser t+1.  The odds ratio is the ratio of the odds of a winning service in t being a winning service in t+1 to the odds of a losing service in t being a winning service in t+1. Three stars indicates significance at the 1% level, two stars indicates significance at the 5% level, and one star indicates significance at the 10% level.