Introduction

Informal news diffusion in organizations has positive and negative consequences. It affects productivity but enhances familiarity with organizational norms. Thus, managers must understand the diffusion process to impede negative aspects and promote positive dissemination. This research primarily focuses on hindering news spread.

Theory

Grosser et al. (2010) posit that negative news diffusion relies on two factors: Shared connections between nodes, and Trust. Here, the first factor is measured by Node Redundancy and the second by Thresholds.

Data

The study uses network data from SG&R law firm (1988-1991), comprising a one-mode network with 34 partners across three offices (Lazega, 2001). It contains the following nodal attributes: gender, age, tenure years, practice, and law school.

Diffusion Models

The first model is a simple SI Model. I selected 1, 4, 8, 12, and 16 random nodes as seeds, depicting scenarios where up to approximately 50% of employees convey rumors. The subsequent plot illustrates seed numbers ascending from 1 to 16.

Regardless of seed count, in each scenario, all nodes become infected after about 10 steps. The networks significant embeddedness (14.26) enabled complete diffusion. To introduce control mechanisms, thresholds were incorporated; for each seeding, they incrementally rose to a minimum value that ensured spread containment.


Minimum thresholds for each seeding strategy are compiled below:

1 4 8 12 16
2 5 6 8 9

Excluding the scenario with one seed node, in the remaining 4 cases, company trust must be so low that, on average, each employee hears news from at least 53% of their neighbours to believe it. In the last scenario, even with the average neighbours as the threshold, the spread isnt contained. To test an alternative strategy, the recovery factor was added to the original five models, starting with 0.01 and increasing to 0.02 and 0.04.

In all scenarios, a recovery rate of 0.04 eventually results in more recovered than infected.

The recovery factor represents forgetting news. Recognizing that people dont typically forget permanently, a waning factor of 0.05 was introduced in the next model. A waning value of 0.05 implies nodes remember forgotten news after 20 steps, the maximum needed to contain news spread in the previous model.

In every seeding scenario, a recovery rate of 0.08 led recovered to exceed infected after approximately 19 steps.

Lastly, trust (thresholds), forgetting (recovery), and remembering (waning) factors are integrated. Waning rate remains constant (0.05), while threshold and recovery rate rise for containment. Plots depict containment conditions with 1 to 16 seed nodes.

Table contains thresholds and recovery rates ensuring diffusion containment for each seeding:

1 4 8 12 16
Threshold 2 3 4 4 4
Recovery Rate 0.01 0.02 0.04 0.04 0.04

Diffusion in the Altered Network

This section delves into altering the network to hinder rumor diffusion.

Removing the Nodes with Degree Higher than Q3

As discussed, node embeddedness facilitates diffusion. Removing nodes with degree centrality and betweenness centrality exceeding a threshold should simplify containment. This section concentrates on degree centrality.

The Q3 of degree centrality is around 0.27. Eliminating nodes exceeding this value retains 75% of nodes while reducing redundancy from 14.27 to 3.96.

The new network comprises 26 nodes. Selecting 1, 4, 8, and 12 random seeds, the minimum thresholds for diffusion containment are as follows:

1 4 8 12
2 3 3 6

Minimum thresholds have significantly decreased compared to the original network.

Next, a recovery-only diffusion model was created. Even for one seed, the needed recovery rate was still 0.04.

A waning factor of 0.05 was added. Even with one seed, a 0.08 recovery rate was required for containment.

Lastly, models incorporating waning (0.05), recovery, and threshold factors were created. Required recovery rates and thresholds show a significant decrease from the original network.

1 4 8 12
Threshold 2 2 2 2
Recovery Rate 0.01 0.01 0.02 0.02

Therefore, less embedded networks make rumors diffusion harder.

Removing the Nodes with Betweenness Centrality Higher than Q3

By removing the nodes with betweenness centrality higher than Q3, the redundancy score decreases to 4.63.

The new network has 25 nodes. I selected 1, 4, 8, and 12 seeds. Without recovery and waning, minimum thresholds for containment are as follows:

1 4 8 12
2 3 3 5

In comparison to the original network, thresholds significantly decreased. Yet, results do not differ much from the previous section.

Models utilizing only recovery or both recovery and waning (0.05) require a minimum recovery rate of 0.04 and 0.08, even with one random seed. Therefore, they do not bring new results.

The final model combines recovery rate, waning, and threshold simultaneously. Recovery rates and thresholds required for containment at a waning rate of 0.05 are in the following table.

1 4 8 12
Threshold 2 2 2 2
Recovery Rate 0.01 0.01 0.02 0.02

These results as well do not differ from the results of the previous section.

Attributing Thresholds Based on Nodal Attributes?

I conduct Chi-squared tests between nodal attributes (Office, Years, Age, Practice, School) and centrality metrics to assess independence. If independence is detected, higher thresholds can be assigned to more embedded nodes.

The results of these test are in the following table (the values within the parentheses indicate the p-value).

Office Years Age Practice School
Degree Centrality Independent (0.3369) Independent (0.3246) Independent (0.4393) Independent (0.3419) Independent (0.3454)
Betweenness Centrality Independent (0.1733) Independent (0.3851) Independent (0.2138) Independent (0.3754) Independent (0.385)

No dependency exists between nodal attributes and centrality measures. Thus, attributing thresholds based on attributes will not contain diffusion.

Conclusion

To curb rumor diffusion, managers can adopt status-quo strategies or alter the network. Reducing rumor conveyors, diminishing trust, and fostering forgetting are status-quo approaches. However, relying solely on recovery is sub-optimal and prolongs rumor persistence. With forgetting and reduced trust at work, even waning (remembering) does not significantly complicate the situation. Finally, reducing highly-connected individuals lowers the needed threshold and recovery rates for containment.