Questions tagged [intervention-analysis]
Intervention analysis estimates the effect of an external intervention on a time-series.
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Comparing intervention/control group
I am planning to conduct a study which is based on an RCT design.
I am intending to conduct an intervention. During this intervention, participants and control group enter some medical data on daily ...
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Interrupted Time Series Design with multiple groups
More of a conceptual question
The standard ITS design is pretty simple, regress:
Y ~ Time + Treatment_Dummy + Time_Since_Treatment
However, what if the scenario was ...
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how to measure the effect of a recurring event?
I have multiple cities with data on theatre visitors and an event as the mentioning of the theatre in the local news.
I want to estimate whether the event of a mentioning lead to more visitors for the ...
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Propensity score matching sample size
I am considering doing a propensity score matching to evaluate the effectiveness of a intervention. However, i only have 193 cases in my treatment group. I have a lot in control group. My outcome is a ...
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Best way to compare income of two groups of people over time
I am planning a research study where, among other things, I want to understand how an intervention changes income in two groups. I plan to collect income data from each individual at three time points....
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Permanent Effects of a Pulse Intervention
I am currently attempting this question and I've managed to solve a and b using the following method:
a)
At t = t*, Δyt* = Δxt* = 1
At t = t*+1, Δyt*+1 = 0.2(1) + 1(1) + 0.7(1) = 1.9
At t = t*+2, Δyt*+...
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How to compare trend for split datasets
I have product price data, at monthly frequency, available for a set of different products. Each of these series have a break point which is the point where we do some kind of intervention. The break ...
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Compare paired before and after composition proportions
I have some data on the composition of purchases by households, before and after an intervention. This composition is known at the number of items or amount spent level within 7 categories, and can be ...
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Finding lagged time series effects
I have a time series with the number of customers and discounts. I suspect that the percentage of discount has a postponed effect.
I tried just lagging the variable and calculating the correlation, ...
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Causal Inference Short Time Series
I am trying to analyse causal inference associated with an intervenion using either Difference-in-Differences or Interrupted Time Series Analysis. I have a discrete time series consisting of data ...
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Time Series Analysis using ARIMA Model in SPPS - Predictor not included in Model/Output
I am very stuck on this and nobody at University seems to be able to help. I am looking at the effects of an intervention (time interruption) on levels of various incident types over the course of 1 ...
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Intervention Impact/time series for data with inconsistent frequencies
What can I do about time series analysis for data with extremely inconsistent frequencies? I am putting together a data set based off satellite imagery where, in some years, I can extract 3-4 data ...
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Can I calculate a repeated measures ANOVA using pre-post difference scores between conditions?
I want to run a within-subject experiment with three interventions. I want to see if these interventions change how my subjects perceive certain stimuli. Now I am torn between two different approaches....
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How to decide on parameters for transfer function in intervention analysis using ARIMA?
I'm very new to Time-Series Analysis and ARIMA so, although I've read a ton of stuff trying to figure it out, I'm sorry if this has already been answered elsewhere.
I'm doing an analysis that's very ...
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What does the superscript triangle (△) symbol mean in graph/causality notation?
I am reading a paper called Robustly Disentangled Causal Mechanisms: Validating Deep Representations for Interventional Robustness and in stating a proposition the authors use a triangle superscript ...
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Find out if stock price is increasing after an event
So I've forgotten all about statistics since my engineering studies and would need a bump in the correct direction.
I have 2 data sets. The first one consists of a bunch of historical events for a ...
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Omitting dummies in panel regression?
I am running a regression studying the effects of different interventions (which appear as dummy variables - they either did or did not have that particular intervention). I don't have a control group ...
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How can i use an ARIMA model to explain the an effect of news regarding COVID-19 on a stock market index?
My thoughts were to model the time series of the stock index up until the particular day for the news I am looking at and forecast using my model. Then I would compare the forecasted result to the ...
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Influence of TV spots on the number of visits to the website (time series problem)
I have hourly data regarding the number of visits to the website. A single record consists of date, time(0-23) and number of visits. In a separate table I have data about the display of advertising ...
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What kind of analysis to use to compare time series trade data
I have a time series data set that gives me the adjusted imports and exports for the period 2003-2016. Suppose a trade agreement was signed in 2009. I want to compare the bilateral trade before and ...
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Time series (or Survival) analysis looking at effect of multiple policy changes over time
I'd like to look at the effect of lockdown policies(announcements) over time on features of the COVID-19 epidemic. I'm not very familiar with different time-series, so i'd like advice on what type of ...
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Subject level variation in repeat measurement designs - representing treatment effects
Consider an experimental situation where each of $n$ participants are randomised to one of two treatments (e.g. active versus placebo).
Our measuring device is known to have some variability in the ...
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What's a proper method for analyzing an intervention in a seasonal time-series?
My data has the following structure (I cannot post the real data):
The data contains 20 shapes (round, squared, triangle), 2 were chosen for simplicity.
The data is recorded for almost 2 years (aprox ...
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Correction for multiple comparisons in a linear mixed effects model with dummy coded categorical predictor
I'm analysing the data from a multi-group randomised controlled trial. Participants were assigned to one of five intervention groups, or a control group. They were tested twice, pre (T1) and post-...
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Monty Hall problem and causality
The Monty Hall paradox is well known, even in this site there are several discussion about it (for example: How can I apply Monty Hall problem correctly? ; Monty hall problem, getting different ...
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Intervention Analysis with binary time series
I need to do a intervention analysis to see if a marketing campaign affected conversion rate.
I would normally would use Causal Impact package to train a time series and then forecast it on the post ...
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Intervention analysis
I'm really struggling to figure out how to construct a model here. Basically what I'm trying to measure is if a school endorsing a statement causes that school to change their policies. I have data on ...
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Assessing impact of concurrent interventions on time series data
I am hoping to assess which interventions create the most change in multiple response variables.
What makes this problem more complicated than typical intervention analysis is the concurrent nature of ...
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Causal inference method for analyzing randomized control trial with covariates / pre intervention observations
I've got a seemingly easy situation, which turns out to be a little more complex than originally thought.
Here's the Setup:
We have a randomized controlled trial. Test and Control groups are the same ...
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Analysis Ideas for Unusual Observational Time Series w/Treatment
I am studying some retrospective time series survey (panel) data, sometimes with an intervening treatment, and would like feedback on an analysis concept to test for a treatment effect.
Each ...
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It is possible to use Time series to predict wether a marketing action is a success or not
Is it possible to use time series could be used to forecast the implementation of an offer ?
Following I am describing an example about how to implement that, is it valid?
Can I use ARIMA time series ...
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What are the models for measuring the time length for impact on a time series?
Is there any methods or models that I can look into for measuring the impact duration of a shock. In my case, I want to evaluate how long will a policy adjustment(raise the interest rate by 1%) will ...
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Comparing data with two timepoints in two groups with categorical classification
I'm hoping you can help me find an analysis best suited for my purpose. I have a dataset structured like this:
Basically, subjects are measured twice and get a score. If the score remains roughly the ...
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Controlling for time with cubic splines in mixed model in R
My aim is to investigate the effect of a change in legislation on behavior in different countries that was measured yearly. All countries of interest adapted the same legislation at different points ...
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Differences between Dynamic Regression Model and Intervention Model?
I am currently studying on dynamic regression and intervention model but I haven't have much resources on hand about the differentiating both of them. I understand that intervention model is a special ...
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Use of Dyanmic Linear Models in Interrupted Time Series
I've been undertaking research in which I use an Interrupted Time Series [ITS] approach to attempt to quantify the effect of a policy intervention.
An ITS approach segments the data into two periods, ...
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Hypothesis testing intervention analysis - pre vs post with expected seasonal change
I have 400 discrete geographic areas of vastly different sizes, where I am recording the number of specific events. Every event is timestamped so I can summerise from daily counts to weekly, monthly, ...
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What is the difference between intervention and conditional distribution?
Suppose that the distribution $P_{C,E}$ is entailed by a structural causal model $\ell$
$C := N_C$
$E := 4C + N_E.$
Given than $N_C$ and $N_E$ are iid $\mathcal{N}(0,1)$ and the graph $C\to E.$ ...
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Why does my mixed model converge using lmer, but no lme?
My aim is to measure the effect of an intervention (policy change) on a dependent variable that was recorded yearly (as was demonstrated at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3415557/).
The ...
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Effectiveness test of intervention on number of cases
Apologies if I'm phrasing this incorrectly,
I want to model the effectiveness of an intervention measure on the number of patients diagnosed with a virus (COVID-19). A hypothesis test of sorts comes ...
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Do I have enough data to build this model?
My aim is to measure the effect of an intervention (policy change) on a dependent variable that was recorded yearly (see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3415557/).
The same policy ...
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Mixed Model Segmented Regression - different length of observation period
I am looking to investigate the effect of an intervention that was applied at 4 different locations. I have yearly measures of the outcome variable and the time point of the intervention is known for ...
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Gradual mean shift intervention
In Cryers textbook: Time Series Analysis: With Applications in R, I came across this:
$$
m_t = \delta m_{t-1} + wS^d_{t-1}\\
\text{where,} \, \,S_t^d =
\begin{array}{cc}
\{ &
\begin{...
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Predictions on transformed series post intervention analysis
I have taken this logged data and performed an intervention analysis:
...
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strucchange for time seires intervention detection/analysis - ARIMA structure and covariates
For my problem, I am dealing with 4 rather short time series (between 21 and 31 points).
I know that an intervention was applied to each of the time series for which I know the exact date.
However, ...
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is there a formula for an innovation outlier regressor in time series intervention analysis
For an innovative outlier, the equations I got from a paper by Tsay, http://docplayer.net/12080848-Outliers-level-shifts-and-variance-changes-in-time-series.html, are these:
$$y_t = f(t) +z(t)\\
f(t) ...
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Time series Intervention Analysis: Identifying (and measuring) trend changes
Based on the question posted here : Interrupted time series analysis for short time series in R
I am trying to analyze the effect of an intervention on the same outcome in different countries. In ...
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Time Series Intervention Analysis with armax function
My aim is to quantify the effect of an intervention on a time series of outcome-measures. For that, I tried to follow this blog post:
https://www.r-bloggers.com/time-series-intervention-analysis-wih-...
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How to control for within-subject covariate in a single-arm, mirror image study design?
I have a mirror image study which consists of one group of subjects, and they have a measure before and another measure after an intervention.
Depiction:
Single group: Measure#1 -> (Intervention) ->...
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Interrupted time series analysis for short time series in R
I am trying to analyze the effect of an intervention on the same outcome in different countries. In addition, I want to control for other time-varying variables that could potentially affect the ...
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